Additionally, tumor tissues were applied to examine the abilities of anti-apoptosis and proliferation by HE, ki-67 IHC, and TUNEL assays, it demonstrated that weaken circRELL1 facilitated anti-apoptosis and proliferation of the xenografts, while strengthened circRELL1 had the opposite effect (Fig. 5H–J). This evidence concerns the gene MKI67 and neoplasm.