RET and sarcoma: Thomas et al. [30] reported that regorafenib, which is an inhibitor of VEGFR-1, − 2 and − 3 and tumor cell signaling kinases (RET, KIT, PDGFR, and Raf), yielded median PFS of 4.6 months in advanced sarcoma patients, which was almost the same as with pazopanib.