NUDT21 and urinary bladder carcinoma: At present, studies have shown that NUDT21 is involved in the occurrence and development of many kinds of tumors, including glioblcomplementarily astoma (13), cervical cancer (14), breast cancer (15, 16), bladder cancer (17), pancreatic ductal adenocarcinoma (18), small cell lung cancer (19), gastric tumorigenesis (20).