Exome analysis of bladder cancer samples across three independent cohorts identified mutations at RXRA S427 in 5–8% of cases, always leading to an amino acid substitution with an aromatic amino acid, phenylalanine (~5%) or tyrosine (~1%) (Cancer Genome Atlas Research Network, 2014; Guo et al., 2013; Van Allen et al., 2014). The gene discussed is RXRA; the disease is urinary bladder carcinoma.