CCND1 and esophageal squamous cell carcinoma: As shown in Figure6B, silenced expression of CCND1 using si CCND1 (si CCND1 + vector) could mimic tumor suppressive effect of miR-503 mimic overexpression (mimic + vector) on ESCC cell proliferation, whereas overexpression of CCND1 (mimic + CCND1) could partially diminish the tumor suppressive effect of miR-503 on ESCC cell lines.