For this study, we selected three genes—OXR1, methylated in ccRCC and pRCC [22]; HOXA9, reported as differentially methylated in chRCC and oncocytomas [23]; and MST1R, highly methylated in ccRCC, that we previously shown to accurately identify ccRCC [14]—to assess their diagnostic performance in an independent series of 120 RCTs. The gene discussed is HOXA9; the disease is chromophobe renal cell carcinoma.