CMTM4 and neoplasm: 786-O-luc cells transfected with LV-NC, LV-circCYP24A1, LV-circCYP24A1 plus miR-421 mimic, and LV-circCYP24A1 plus sh-CMTM4 were subcutaneously injected into nude mice and tumor growth was evaluated (Fig. 7A).