Whereas we confirmed the high RASSF1A promoter methylation levels in pRCC previously reported by Gonzalgo and co-workers [17], we additionally found that PTGS2 promoter methylation as a likely candidate marker for ccRCC, something that might permit a more accurate detection of this tumor type in limited tissue or needle-aspirate samples. Here, PRCC is linked to nonpapillary renal cell carcinoma.