PTGDR and nonpapillary renal cell carcinoma: In the TCGA-KIRC methylation data, the methylation levels of 13 CpG sites of ZNF582-AS1 DNA (cg25267765, cg24733179, cg24039631, cg22647407, cg20984085, cg13916740, cg11740878, cg09568464, cg08464824, cg07778983, cg07135042, cg02763101, cg01772700) were significantly higher in ccRCC compared with adjacent normal renal tissues (Additional file 2: Figure S1 a, b), and the methylation levels of these 13 CpG sites were negatively correlated with ZNF582-AS1 expression (Additional file 2: Figure S1 c).