AKR1D1 and cancer: Among 99 mutations, only 5 were presented in COSMIC, including missense mutations in PSMD4, TAPT1, AKR1D1, SNCAIP and SNX13. However, frequencies of the 5 mutations were extremely low (no more than 2 cases) among more than 20,000 tested cancer samples in COSMIC database (Table S9), implicating that these mutations are unlikely key cancer driver mutations.