NR4A1 and endometrial cancer: This study sought to determine whether there is a significant difference in 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 between an endometrial biopsy taken immediately prior to the start of surgery and the hysterectomy specimen.