Metanephric adenoma lacks the gains of chromosomes 7 and 17 and loss of Y that are typical of papillary renal cell carcinoma and papillary adenoma.

Metanephric adenoma has morphologic similarities to papillary renal cell neoplasms. Cytogenetic studies of papillary renal cell carcinoma and papillary adenoma have shown frequent gains of chromosomes 7 and 17 and loss of the Y chromosome. Some cytogenetic studies have supported the hypothesis that metanephric adenoma is related to papillary renal cell neoplasia; others have not. Seven metanephric adenomas were studied with fluorescence in situ hybridization in paraffin sections using centromeric probes for chromosomes 7, 17, and Y diluted 1:100 with tDenHyb1 buffer. The signals in 100 to 200 nuclei were counted in each tumor. Samples of histologically normal renal cortical tubule epithelium were used as controls. In all seven metanephric adenomas, the results for chromosomes 7 and 17 were similar: a high percentage of nuclei with two signals (range, 75 to 85%; median, 79%). Normal kidney showed similar results (range, 78 to 88%; median, 84%). The Y chromosome was present in all three of the tumors from males (range, 86 to 89% of nuclei; median, 87%). Normal kidney gave similar results (range 82% to 91%, median 84%). The presence of chromosomes 7, 17, and Y in metanephric adenomas is similar to their presence in normal kidney. Metanephric adenoma lacks the frequent gains of chromosomes 7 and 17 and losses of the Y chromosome that are typical of papillary renal cell neoplasms, supporting the notion that metanephric adenoma is not related to papillary renal cell carcinoma and papillary adenoma. Genetic analysis of chromosomes 7, 17, and Y may facilitate discrimination of metanephric adenoma from papillary renal cell carcinoma in difficult cases.     

Fluorescence in situ hybridization study of aneuploidy of chromosomes 7, 10, X, and Y in primary and secondary glioblastomas

The aneuploidy of autosomes 7, 10, and sex chromosomes (X and Y) was analyzed in a series of 44 primary (de novo) and 20 secondary glioblastomas using fluorescence in situ hybridization (FISH) on smear preparations of glioma tissue. The tumors were screened for trisomy 7, monosomy 10, as well as loss of the Y chromosome and disomy of the X chromosome in male subjects, and monosomy of the X chromosome in female subjects. We found that taken alone or in combination, these chromosomal abnormalities do not appear to be characteristic of a glioblastoma subtype; therefore, they do not allow the differentiation between primary and secondary glioblastomas. Also, the loss of a chromosome 10 appears to be an earlier event than a gain of a chromosome 7 for the genesis of a secondary glioblastoma.     

In situ hybridization analysis of HPV 16 DNA sequences in early cervical neoplasia

The authors examined 18 cervical intraepithelial neoplasms (CIN) for the presence of human papillomavirus (HPV) DNA sequences by Southern blot hybridization and DNA-DNA in situ hybridizations for HPV DNA sequences and compared the epithelial distribution of HPV 16 DNA sequences with HPV 6/11 sequences in selected condylomas. Fifteen of the 18 CIN lesions contained HPV 16 DNA as determined by Southern blot hybridization. With the use of biotinylated HPV 16 DNA probes, 10 of the 18 were positive by in situ hybridization, 9 of which were also positive by Southern blot hybridization. In situ hybridization to HPV 16 probes was found primarily in areas of CIN which contained either maturation or koilocytotic atypia, although in two cases hybridizing sequences were detected in superficial cells from epithelium with no discernible maturation. Staining in both condylomas and CIN lesions varied in distribution and intensity. However, in some CIN lesions staining from cell to cell varied considerably. This greater variability in staining appeared to correlate with greater morphologic variations which characterize CIN, and which may influence greater variation in HPV DNA replication. Thus, some differences in patterns of hybridization for HPV DNA between CIN and condylomas may be explained by morphologic differences in the two classes of lesions. Differences in viral gene expression between condylomas and CIN and their relationship to morphologic findings remain to be clarified.     

Renal cell carcinoma with mixed features of papillary and clear cell cytomorphology: a fluorescent in situ hybridization study

We performed fluorescent in situ hybridization (FISH) to investigate the numeric change of chromosomes 7, 17, and Y and loss of chromosome 3p in “papillary renal cell carcinomas (RCC) with extensive clear cell changes (CCC).” Consecutive cases of RCC over a 12-year period were reviewed to identify “papillary RCC with extensive CCC.” Immunostaining for cytokeratin 7 and alpha-methylacyl-CoA racemase (AMACR) and FISH for chromosomes 7, 17, Y, and 3p were applied. Of the total of 521 RCC retrieved, there were 49 RCC with papillary architecture and clear cell areas that could be divided into: Group 1 (12 cases), typical clear cell RCC with focal areas of papillary formation; Group 2 (28 cases), focal typical papillary RCC having papillary architecture with extensive CCC; and Group 3 (nine cases), RCC with an admixture of eosinophilic/clear cytoplasm and solid/papillary architecture. Group 1 showed negative immunoreactivity for CK7 and AMACR and absence of numeric chromosomal gain or loss of chromosomes 7/17 and Y. Groups 2 and 3 showed variable reactivity for CK7 and AMACR. Tumors in group 2 and five in group 3 showed trisomies of chromosomes 7 and/or 17 with or without loss of chromosome Y. Loss of small arm 3p was observed in groups 1 and 3 but not in group 2 tumors. In conclusion, papillary RCC may show phenotypical CCC mimicking clear cell RCC. In a small number of cases with mixed histopathological features, FISH is helpful in subtyping RCC.     

Acquired cystic disease-associated renal cell carcinoma with gain of chromosomes 3, 7, and 16, gain of chromosome X, and loss of chromosome Y

Acquired cystic disease (ACD)-associated renal cell carcinoma (RCC) has been recently described. To date, there are no reports on genetic findings of G-band karyotype of ACD-associated RCC. In this article, we report the first report of G-band karyotype of ACD-associated RCC. A 66-year-old Japanese man was found to have a left renal tumor during the follow-up of hemodialysis consequent to chronic renal failure. Left nephrectomy was performed. Histological examination of three tumors in the left kidney showed the cribriform or microcystic growth pattern of neoplastic cells with eosinophilic cytoplasm, and many oxalate crystals were observed. The G-band karyotype of ACD-associated RCC showed 49, X, +X, −Y, +3, +7, +16. These chromosomal abnormalities resemble those of sporadic papillary RCC that has been previously reported. Finally, we suggest that this tumor may show a close relationship between ACD-associated RCC and papillary RCC, but a large-scale study will be needed to clarify the relationship between ACD-associated RCC and papillary RCC.     

Clear cell papillary renal cell carcinoma with angiomyomatous stroma: a histological,immunohistochemical, and fluorescence in situ hybridization study

Clear cell papillary renal cell carcinoma (CCPRCC) is a novel tumor entity that was recently recognized as a new distinct epithelial tumor within the current classification system. Nonclassic morphologic variants have rarely been reported. We present six challenging cases of CCPRCC with prominent (>75 %) tubular, acinar, and/or solid component and angioleiomyomatous stroma. The tumors lacked well-organized papillary architecture. All tumors had a variously thick capsule formed by a layer of bands of smooth muscle. The leiomyomatous tissue often entirely encased patches of tubular structures, or it formed only small leiomyomatous islands within the epithelial component. There was a remarkable relationship between the vascular network and the epithelial component in the sense that every single tubule or acinus was associated with a fine capillary network, with the capillaries intimately surrounding the tubular or acinar circumference. CCPRCC with variant morphology expressed carbonic anhydrase IX (CA-IX) in cup-shaped distribution. In addition, the tumor cells stained positive for cytokeratin 34betaE12, CK7, and vimentin. Renal cell carcinoma (RCC), P504s/AMACR, Melan A, and HMB45 were negative in tumor cells in all cases examined. Fluorescence in situ hybridization studies showed the presence of a normal copy number for chromosomes 7, 17, 3q, and 3p. CCPRCC with variant morphology seems to have a favorable prognosis. In the current series, tumor stage was low at presentation, and none of the patients had local recurrence or metastatic disease. The distinction between CCPRCC with variant morphology and clear cell RCC is critical because no case of CCPRCC has behaved aggressively.     

Renal mucinous tubular and spindle carcinoma lacks the gains of chromosomes 7 and 17 and losses of chromosome Y that are prevalent in papillary renal cell carcinoma.

Mucinous tubular and spindle cell carcinoma of the kidney is an uncommon, distinctive neoplasm characterized by the proliferation of cuboidal and spindle cells arranged in tubular or sheet-like arrays, typically with a mucinous or myxoid background. The most important differential diagnostic consideration of mucinous tubular and spindle cell carcinoma is papillary renal cell carcinoma, type 1, with sarcomatoid transformation. The aim of our study is to investigate the pattern of possible gains or losses of chromosomes 7, 17 and Y in 10 mucinous tubular and spindle cell carcinomas with interphase fluorescence in situ hybridization (FISH). Four-micron sections were obtained from paraffin blocks representative of the tumors and including adjacent non-neoplastic renal parenchyma from 10 patients. The patients' ages ranged from 20 to 80 years (mean: 62 years); eight were female, while two were male. FISH analysis was performed with centromeric probes for chromosomes 7, 17 and Y. One hundred fifty to 200 nuclei from each case were scored for hybridization signals and non-neoplastic parenchyma served as control tissue. We found that renal mucinous tubular and spindle carcinoma lacks the gains of chromosomes 7 and 17 and losses of chromosome Y that are typical of papillary renal cell carcinoma. FISH analysis with centromeric probes for these chromosomes is potentially helpful in differentiating mucinous tubular and spindle cell carcinomas from papillary renal cell carcinomas.     

Specific loss of chromosomes 1, 2, 6, 10, 13, 17, and 21 in chromophobe renal cell carcinomas revealed by comparative genomic hybridization.

We analyzed 19 chromophobe renal cell carcinomas by means of comparative genomic hybridization. Two tumors revealed no numerical abnormalities. In the remaining 17 cases we found loss of entire chromosomes with underrepresentation of chromosome 1 occurring in all 17 cases; loss of chromosomes 2, 10, and 13 in 16 cases; loss of chromosomes 6 and 21 in 15 tumors; and loss of chromosome 17 in 13 cases. The loss of the Y chromosome was observed in 6 of 13 tumors from male patients, whereas 1 X chromosome was lost in 3 of 4 tumors obtained from females. Comparative genomic hybridization results were verified by interphase cytogenetics. We conclude that a specific combination of multiple chromosomal losses characterizes chromophobe renal cell carcinomas and may help to differentiate them unequivocally from other types of kidney cancer.     

Allelic loss on chromosomes 3p, 5q and 17p in renal cell carcinomas

Lossof-heterozygosity (LOH) has been studied on 3p (von Hippel-Lindau gene locus), 5q and 17p (p53 gene locus) by a polymerase chain reaction (PCR)-based strategy in 42 sporadic renal cell carcinomas (RCC). LOH at seven micro-satellite loci on 5q was Investigated because a tumor sup presser gene on 5q involved In the development and/or progression of RCC has not yet been identified. LOH was found In seven (17%) RCC at single or multiple locl on 5q, 38% (11/29 Informative cases) on 3p, and 6% (2/35 Informative cases) on 17p. Replication error (RER) was present in 10% (4/42) RCC at single or multiple loci. The minimum region of deletion on 5q to account for LOH was mapped to 5q31.1 (interferon regulatory factor-1; IRF-1 locus), where LOH was detected In 23% (6/26 Informative cases). LOH on 3p and 5q occurred In both stage 2 and more advanced (stage 3 and 4) tumors at similar incidences (41 and 33% on 3p; and 24 and 22% on 5q, respectively), suggesting that LOH on these chromosomes Is an early genetic event. All RCC exhibiting LOH on 3p or 5q (IRF-1 locus) were the clear cell or the mixed clear and granular cell types. These findings suggest that LOH on 3p and 5q plays an important role in the genesis of clear cell RCC. In addition, only one tumor exhibited LOH on both 3p and 5q, which suggests that LOH occurs not sequentially but independently.     

Detection of numerical alterations for chromosomes 7 and 12 in benign thyroid lesions by in situ hybridization. Histological implications.

Polysomies of chromosomes 7 and 12 have been frequently observed by conventional cytogenetics in a subgroup of thyroid follicular adenomas and in some cases of thyroid goiters. To further study possible cytogenetic similarities between these two types of thyroid lesions, we have used fluorescence in situ hybridization (FISH) to detect polysomies of chromosomes 7 and/or 12 in isolated nuclei from frozen and paraffin-embedded material of goiters and thyroid follicular adenomas and compared results with previous ones obtained by flow cytometry and conventional cytogenetics. With a set of two alpha-satellite DNA probes specific for the centromeric regions of chromosomes 7 and 12, used either separately (single-target fluorescence in situ hybridization) or simultaneously (double-target fluorescence in situ hybridization), we detected polysomies of chromosome 7 in 35.7% of the thyroid follicular adenomas and in 10.7% of the goiters. Polysomies of chromosome 12 were detected in 29.6% of the thyroid follicular adenomas and 6.7% of the goiters. The significantly higher frequency of adenomas with numerical alterations for chromosomes 7 and/or 12 supports the idea of a biological continuum and karyotypic evolution between both lesions. It is also noteworthy that polysomies of chromosomes 7 and/or 12 were observed only in lesions with an exclusive (or predominant) microfollicular histological component, as detected by enzymatic in situ hybridization on frozen sections.     

Detection of numerical and structural alterations and fusion of chromosomes 16 and 1 in low-grade papillary breast carcinoma by fluorescence in situ hybridization.

Intracystic papillary breast tumors, including intraductal papilloma and low-grade intracystic papillary carcinoma, constitute a group for which differential diagnosis is frequently difficult. We examined the status of chromosomes 16 and 1 by multicolor fluorescence in situ hybridization (FISH) analyses and the DNA ploidy patterns by flow cytometry in 26 intracystic papillary tumors. Alterations of chromosomes 16 and 1 were detected by FISH in 93 and 85%, respectively, of 14 low-grade papillary carcinomas, and the latter alterations always concurred with the former. Two-color FISH using probes for the D1Z1 (1q12) and D16Z2 (16cen) loci or the D1Z1 and D16Z3 (16q11) loci showed that fusion of chromosomes 16 and 1, mostly with breakpoints distal to 16q11.2 and proximal to 1q12, occurred in 77% of the papillary carcinomas. DNA aneuploidy was detected in 6% of these carcinomas. No papilloma showed these chromosome alterations or DNA aneuploidy. Chromosome 16 and 1 fusions appeared to occur frequently in diploid breast carcinomas and to be involved in the acquisition of a malignant phenotype by duct epithelial cells. We suggest that two-color FISH methods for detecting 1;16 fusions might be applicable as supportive methods for the differential diagnosis of intracystic papillary breast tumors.     

End-stage kidney disease: gains of chromosomes 7 and 17 and loss of Y chromosome in non-neoplastic tissue

The aim of this study was to determine the copy number changes of chromosomes 7, 17, 3p, and Y in a non-neoplastic tubular epithelium in end-stage kidney disease (ESKD). Seventeen kidneys from 11 patients with ESKD were retrieved from the archive files. Non-neoplastic kidney tissue in these cases was examined separately. Tissues containing papillary adenomas (PA), clear (CRCC) and papillary renal cell carcinomas (PRCC), and myxoid liposarcoma (LPS) were examined using the same probes and compared with non-neoplastic tissue. Tubular changes in the kidney parenchyma were classified into three types: (1) The vast majority of tubules were entirely atrophic; (2) Several tubules were hyperplastic, i.e., tubules with undifferentiated large epithelial cells, in which it was impossible to establish the specific type of a renal tubulus; (3) Dysplastic tubules were dilated, sometimes wrinkled. The basal membranes were lined by large eosinophilic epithelial cells with polymorphic nuclei and pseudostratification. Nucleoli were clearly visible. These tubular changes were multifocal with a haphazard distribution within the atrophic parenchyma. PA were detected in nine patients, of whom eight patients also revealed an additional tumor type(s) (4x CRCC, 3x PRCC, 1x PRCC, and CRCC). One patient had a CRCC only, another had a combination of PRCC and LPS. Chromosomal abnormalities were found in the second and third group of tubular changes, i.e., in hyperplastic and dysplastic tubules. Trisomy of chromosome 7 was detected in six cases, whereas trisomy of chromosome 17 in eight cases. A combination of both trisomies was found in five cases. Loss of chromosome Y was found in two cases. Fluorescence in situ hybridization on tissues containing papillary adenomas, renal cell carcinomas, and liposarcoma revealed expected results, i.e., trisomy of chromosomes 7 and 17 in all PAs and PRCC. No gains were present in CRCC and LPS. Loss of Y was found in six PA, five PRCC, and one LPS; loss of X was found in two CRCCs. We suggest that chromosomal changes typical of the papillary renal cell lesions, i.e., trisomies of chromosomes 7 and 17, are very frequent in non-neoplastic parenchyma of the end-stage kidney, and they have a tendency to a multifocal occurrence.     

Detection of extra chromosomes 12 by fluorescent in situ hybridization (FISH) in ovarian stromal tumors. Study of 12 cases and review of the literature

Chromosomic aberrations play a major role in the initiation and the progression of benign as well as malignant tumors. In particular, trisomy 12 is frequently observed in female genitourinary tract tumors and constitutes a recurrent and often unique anomaly in stromal ovarian tumors such as fibrothecomas. Today, the genetic analysis of fresh or fixed solid tumors is enabled by the fluorescent in situ hybridization method (FISH). Using FISH and/or conventional cytogenetics, we analysed 12 ovarian stromal tumors (6 fibromas, 3 fibro thecomas and 3 thecomas). All of these tumors were benign and trisomy 12 was observed in all cases. Moreover, 3 cases presented trisomy and tetrasomy for chromosome 12 simultaneously. The high frequency of trisomy 12 in this tumor type suggests that this abnormality might be implicated in ovarian tumorigenesis.     

Detection of Gallibacterium spp. in chickens by fluorescent 16S rRNA in situ hybridization

Gallibacterium has recently been included as a new genus of the family Pasteurellaceae Pohl 1981, which encompasses bacteria previously reported as Pasteurella anatis, "Actinobacillus salpingitidis," and avian Pasteurella haemolytica-like organisms. So far, identification has exclusively relied on phenotypic characterization. We present a method based on a cyanine dye 3.18-labeled in situ hybridization probe targeting 16S rRNA to allow specific detection of bacteria belonging to the genus Gallibacterium. The probe, GAN850, showed no cross-reactivity to 25 other poultry-associated bacterial species, including members of the families Pasteurellaceae, Enterobacteriaceae, and Flavobacteriaceae, when cross-reactivities were evaluated by whole-cell hybridization. The probe was further evaluated by hybridization to formalin-fixed spleen and liver tissues from experimentally infected chickens, in which it proved to be useful for the detection of Gallibacterium. Additionally, determination of the spatial distribution and the host cell affiliation of Gallibacterium at various times during the infection process was possible. In conclusion, the in situ hybridization technique described may be of use as a diagnostic tool as well as for studies to elucidate the pathogenesis of Gallibacterium infections in chickens.     

Estimation of aneuploidy for chromosomes 3, 7, 16, X and Y in spermatozoa from 10 normospermic men using fluorescence in-situ hybridization

Fluorescence in-situ hybridization (FISH) is a fast and efficient method of estimating aneuploidy in human spermatozoa. In this study, we have estimated baseline disomy frequencies in spermatozoa from a group of 10 normospermic men, using stringent scoring criteria. A triple- probe FISH procedure was used for chromosomes 3, X and Y, while a double-probe FISH method was used for chromosomes 7 and 16. A total of 101273 spermatozoa were scored for chromosomes 3, X and Y, resulting in 97.83% haploidy (3X or 3Y), 0.39% disomy (33X, 33Y, 3XX, 3YY or 3XY) and 0.35% diploidy (33XX, 33YY or 33XY). A total of 100760 spermatozoa were scored for chromosomes 7 and 16, giving 98.9% haploidy (716), 0.11% disomy (7716 or 71616) and 0.27% diploidy (771616). Disomy frequencies for individual chromosomes differed (chromosome 3, 0.20%; chromosome 7, 0.05%, chromosome 16, 0.06%; X + Y, 0.19%). The frequency of disomy 3 was significantly higher than disomy 7 (P = 0.019) and disomy 16 (P = 0.022), while the frequency of sex chromosome disomy was significantly higher than disomy 7 (P = 0.0058) and disomy 16 (P = 0.0067), but not disomy 3 (P = 0.73). The disomy and diploidy (0.27- 0.35%) estimates obtained for this normospermic population were generally low and were similar to other recent reports.      

Clonal aberrations of chromosomes X, Y, 7 and 10 in normal kidney tissue of patients with renal cell tumors.

By means of G-banding techniques, chromosome aberrations were studied in short-term cultures of normal renal parenchymal cells from 45 patients with renal cell carcinoma. Clonal chromosomal aberrations were detected in 29 patients; loss of the Y chromosome as well as trisomy X, 5, 7, 9, 10, 12, and 18 was found. Chromosomes 7 and 10 were involved preferentially. Results of fluorescence in situ hybridization with chromosome 7- and 10-specific DNA probes on non-cultured normal kidney cells suggested that the aberrations developed in vivo.     

用细胞原位杂交方法检测NPY mRNA在PC12细胞中的表达

目的：建立ＮＰＹ ｍＲＮＡ物细胞原位杂交检测方法,并以ＮＧＦ为诱导因子研究Ｄｅｘ对大鼠嗜铬细胞瘤ＰＣ１２细胞中ＮＰＹｍＲＮＡ表达的影响。方法：采用细胞原位杂交方法。方法：ＮＧＦ具有诱导ＮＰＹ基因表达的生物学效应且呈剂量效应关系;Ｄｅｘ对ＮＰｘＲＮＡ表达具有双相调节效应,即早期（〈８ｈ）可促进ＮＧＦ的诱导作用,而晚期（〉１６ｈ）则具有抑制作用（Ｐ〈０．０１）,但单独Ｄｅｘ对ＮＰＹｍＲＮＡ表达无显著影     

Aneusomy of chromosomes 7, 8, and 17 and amplification of HER-2/neu and epidermal growth factor receptor in Gleason score 7 prostate carcinoma: a differential fluorescent in situ hybridization study of Gleason pattern 3 and 4 using tissue microarray.

Recent evidence shows that the proportion of poorly differentiated prostate carcinoma (Gleason pattern [GP] 4/5) is a surrogate factor for biochemical failure after radical prostatectomy (RP). However, little is known about specific molecular and cytogenetic changes in this aggressive component of localized prostate cancer. We constructed a tissue microarray containing areas of GP 3 and 4 from formalin-fixed radical prostatectomy specimens of 39 patients with Gleason score 7 carcinoma (>or=50% GP 4), known pathologic staging parameters (stage < T3b), and biochemical failure data (mean follow-up, 30 months; range, 5 to 74 months). Interphase fluorescent in situ hybridization (FISH) was performed on 5-microm microarray sections using pericentromeric probes to chromosomes 7, 8, and 17 and probes for the HER-2/neu and epidermal growth factor receptor (EGFR) genes. Low-level amplification of HER-2/neu was found in 26% of cases (3 to 5 signals per nucleus, corrected for chromosome 17 aneusomy). Aneusomy of chromosomes 7, 8, and 17 was identified in 21%, 15%, and 5% of cases, respectively. All aberrations occurred almost exclusively in GP 4 carcinoma (8 of 8 aneusomies 7, 2 of 2 trisomies 17, 9 of 10 HER-2/neu amplifications, and 5 of 6 aneusomies 8; P < .001). The presence of HER-2/neu amplification was associated with high tumor volume (>2.0 cm(3), P = 0.004). Among patients with negative surgical margins, gain of chromosome 7 was associated with biochemical failure after RP (P =.004, log-rank). Amplification of the EGFR gene occurred in only 1 case (3%). Significant differences in HER-2/neu amplification and gain of chromosomes 7, 8, and 17 were detected between GP 4 prostate carcinoma and GP 3. The frequency of aberrations increased with tumor volume. Chromosome 7 abnormalities may play an important role in cancer progression in margin-negative patients. EGFR amplification was rare, suggesting that this oncogene is not altered at the gene copy number level.     

Complex chromosome rearrangement involving chromosomes 1, 4 and 16 revealed by fluorescence in situ hybridization

A 7-year-old boy with mental retardation had apparently balanced reciprocal translocations, involving the telomeric regions of chromosomes 1p and 4q, which was detected by routine chromosome analysis. Fluorescence in situ hybridization (FISH) was used and also revealed the telomeric region of chromosome 16p to be involved in a still apparently balanced translocation-complex, impossible to discover with classical cytogenetic analysis. We want to emphasize the importance of FISH in detecting small chromosomal aberrations. We discuss whether the abnormal phenotype is caused by unbalanced karyotype with cryptic undetected translocations or small deletions or mutations in the translocation-breakpoints.