SIRT2-dependent IDH1 deacetylation at K224 impairs its enzymatic activity and represses its malignant behaviors in CRC.129 Specially, studies also found that IDH1 is significantly downregulated in clear cell renal cell carcinoma (ccRCC) compared with normal kidney cells, suggesting that IDH1 may function as a candidate tumor suppressor for ccRCC.130,131. This evidence concerns the gene IDH1 and nonpapillary renal cell carcinoma.