BMI1, a member of PRC1 that binds to the RING2/RING1b subunit to form a functional E3 ubiquitin ligase, was found to be overexpressed in various tumors, including endometrial cancer, laryngeal carcinoma, prostate cancer, and hepatocellular carcinoma [11]. The gene discussed is RNF2; the disease is hepatocellular carcinoma.