DRGX and nonpapillary renal cell carcinoma: The nine-mRNA methylation signature, including DMRTA2, DRGX, FAM167A, FGGY, FOXI2, KRTAP2-1, TCTEX1D1, TTBK1, and UBE2QL1, may be a useful prognostic biomarker for ccRCC patients.