Platelet derived growth factor receptors (PDGFRs) are tyrosine kinase receptors, that are involved in many normal cellular processes, including organogenesis, cell proliferation, angiogenesis, etc. These receptors come in two isoforms called PDGFRA and PDGFRB. PDGFR signaling can be altered by gene amplification or activating mutations. These aberrations in PDGFR have an incidence of about 30% in cancer. Tumor types for which PDGFR is altered in at least 10% of cases includes GIST, glioblastoma, lung, melanoma, bladder, prostate, colorectal and ovarian cancers.