TYMP and neoplasm: Capecitabine (Chugai Pharmaceutical Co., Ltd., Tokyo, Japan) is designed to be specifically transformed from 5’-deoxy-5-fluorouridine (5’-DFUR) to 5-FU by thymidine phosphorylase (TP), which is in higher concentrations in tumor tissues than in normal tissues, with the aim of reducing the gastrointestinal and hematological toxicities of 5-FU [7].