Although showing a slightly higher mutational rate in some “colorectal-like” genes (KRAS, APC, CTNNB1) than BLCA, UCg mainly harboured frequent alterations in distinct urothelial-like genes (e.g. TERT, RB1, CDKN1A, ARID1A and KDM6A) as well as TP53 and PIK3CA. A particularly conspicuous aspect is the high level of TERT mutations in UCg which differ from UAC or BAC with only low numbers of TERT mutated cases [40]. The gene discussed is ARID1A; the disease is bladder transitional cell carcinoma.