A total of 6 (i.e. GREM1 (region i), LAD1 (region i and ii), NEFH (region i), NEURL (region ii), SFRP1, and GATA5) out of the 11 published, promising methylation markers were validated as predictors of CSS in a population-based series of ccRCC patients independent of standard prognostic variables. The gene discussed is SFRP1; the disease is nonpapillary renal cell carcinoma.