To identify circRNAs with a putative function in ccRCC initiation/progression, we selected circRNAs from host genes with putative roles in angiogenesis and hypoxia in ccRCC and other cancers including EGLN3, NOX4, and RHOBTB3 [23,24,25,26,27]. This evidence concerns the gene NOX4 and nonpapillary renal cell carcinoma.