CircEPSTI1 promotes cervical cancer proliferation in vivo. (A) Tumor in the mouse xenograft model. (B) The nude mice were subcutaneously injected with HeLa cells and subjected to distinct treatments (i.e., si-cEPSTI1 or scramble). The volume curves of tumors are shown. **, P < 0.01 compared to the negative control group. (C) The immunohistochemistry analysis was performed for xenograft tumors and the representative images of ki-67 expression are presented. Scale bar = 50 μm.