In three datasets that included patients with metastatic ccRCC (GSE22541, GSE85258 and GSE113204), we demonstrated that these 18 ARGs genes had excellent efficacy in discriminating primary ccRCC from metastases with AUC = 0.991, 0.952 and 1.000, respectively (Figure 2e). This evidence concerns the gene SERPINA2 and nonpapillary renal cell carcinoma.