CA9 and nonpapillary renal cell carcinoma: Our results confirmed hypomethylation of CA9[50] and identified new, at the time of preparation of the manuscript, hypomethylated genes known to be overexpressed in ccRCC, including nicotinamide N-methyltransferase (NNMT), caveolin 1 (CAV1) and cyclin D1 (CCND1).