ALDH1A2 and nonpapillary renal cell carcinoma: By mining the data from TCGA-KIRC and CPTAC-PDC000127 cohorts, we discovered the differential expression patterns among the 19 ALDHs genes, only ALDH1L2, ALDH3A1 and ALDH3B1 exhibited upregulation in ccRCC, while other 13 molecules, namely ALDH1A2, ALDH1B1, ALDH1L1, ALDH2, ALDH3A2, ALDH3B2, ALDH4A1, ALDH5A1, ALDH6A1, ALDH7A1, ALDH8A1, ALDH9A1 and ALDH16A were found to be significantly downregulated (Fig. 1A, B and Supplementary Fig. 1A, B).