MKI67 and neoplasm: IHC staining was performed to tumor mass, the results showed tumors in shER-α36 groups exhibited significantly lower ER-α36 expression and Ki67 proliferation index vs. the control group, whereas tumors in ER-α36-LV groups exhibited up-regulated ER-α36 expression and high staining intensity of Ki67 (Figures 5E, F).