TYMP and metastatic colorectal cancer: Trifluridine/tipiracil (TAS-102, Lonsurf®), a novel oral anti-tumor agent combining an anti-neoplastic thymidine-based nucleoside analogue (trifluridine, FTD) with a thymidine phosphorylase inhibitor (tipiracil hydrochloride, TPI) presents a new treatment option for metastatic colorectal cancer (mCRC) patients refractory or intolerant to standard therapies.