Affiliation: | aBroad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, 02142;;bDepartment of Computer Science, Stanford University, Stanford, CA, 94305;;cDivision of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115; and;dHoward Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02142 |