CDKN2A and renal cell carcinoma: CDKN2A mutation, hypermethylation, or deletion was found in 15.8% of tumors, with alterations in each RCC subtype accounting for 16.2% of ccRCC, 5.0% of type 1 PRCC, 18.6% of type 2 PRCC, 100% of CIMP-PRCC, and 19.8% of ChRCC (Figure 2B).