The immunohistochemical expression of commonly studied biomarkers in endometrial cancer window studies, including Ki-67, phosphorylated markers of the PI3K-Akt-mTOR and insulin signaling pathways and hormone receptors, is significantly lower in the hysterectomy specimen compared with an endometrial biopsy taken immediately prior to the commencement of surgery. Here, MKI67 is linked to endometrial cancer.