It has been found that MAD2L1 expression in 14 tumor samples is higher than in normal samples, including bladder urothelial carcinoma, breast invasive carcinoma, cholangio carcinoma, colon adenocarcinoma, esophageal carcinoma, glioblastoma multiforme, head and neck squamous cell carcinoma, kidney renal clear cell carcinoma, liver HCC, lung adenocarcinoma, lung squamous cell, prostate adenocarcinoma, stomach adenocarcinoma, and uterine corpus endometrial carcinoma (Fig. 1A). The gene discussed is MAD2L1; the disease is bladder transitional cell carcinoma.