Moreover, qRT-PCR verified seven apoptosis-related genes (APP, DOCK8, IFI44, MDK, SLC27A2, TNFAIP2, WNT5A) with at least 2 fold changes by means of 2−ΔΔCt method, finding that APP, SLC27A2 and WNT5A had a low expression, while DOCK8, IFI44, MDK, TNFAIP2 had a high expression in ccRCC tumor tissues (Figure 8J). Here, IFI44 is linked to nonpapillary renal cell carcinoma.