Furthermore, MKRN2 mRNA (Fig. 1C-1D and Fig. S1K) and protein (Fig. 1E-1F) expression in the four ccRCC cell lines and samples was significantly downregulated from levels in human normal kidney epithelial cells (HEK293) and paired adjacent non-tumor tissues. This evidence concerns the gene MKRN2 and nonpapillary renal cell carcinoma.