Subsequently, circAFAP1 knockdown reduced the proliferation ability of ccRCC cell lines verified by CCK8 assays and colony formation assays whereas co-transfected miR-374b-3p inhibitor counteracted this effect to a large extent and restored completely the reduction after VEGFA overexpression (Fig. 4B, C). Here, VEGFA is linked to nonpapillary renal cell carcinoma.