Regorafenib is an oral multi-kinase inhibitor that targets signaling pathways involved in tumor angiogenesis (VEGFR1-3 and TIE2), oncogenesis (KIT, RET, RAF1, and BRAF), and the tumor microenvironment (PDGFR, FGFR, and CSF1R). This evidence concerns the gene RET and neoplasm.