RXRA and urinary bladder cancer: Bladder cancer is the second most common urogenital cancer with 550 000 new cases every year worldwide.1 Whole-exome sequencing of bladder cancer patients identified a hotspot mutation within the gene encoding the retinoid X receptor α (RXRα) involving Ser427 changing to Phe and less frequently to Tyr (RXRαS427F/Y).2