SFRP1 and nonpapillary renal cell carcinoma: The hypermethylated and under-expressed genes included Secreted Fzd-related protein 1 (SFRP1), which was consistent with previous ccRCC studies (Awakura et al., 2008; Gumz et al., 2007), and PIC3K2G, which was a known cancer susceptibility gene (Brown et al., 2015) (Table S2).