Protein tyrosine kinase inhibitors in cancer therapy

The tyrosine kinase inhibitors (TKI) are small molecules of low molecular weight that inhibit tyrosine kinases, enzymes responsible for the activation of signal transduction cascades. Currently, a number of TKI received approval in various cancers, while others are in clinical development process: TKI are specifically clinically active when they target a tyrosine kinase (TK) with constitutional activity subsequent to a mutation, being then a master-gene driving transformation and tumour progression. Already, this drug-family provides a major therapeutic weapon against cancer.