MKI67 and neoplasm: At baseline, tumor regions were distinguishable from the stromal areas by an abundance of ovarian epithelial markers, including epithelial cell adhesion molecule (EPCAM), Estrogen Receptor alpha (ERα), Progesterone Receptor (PR), human epidermal growth factor receptor 2 (HER2), and the proliferative marker Ki-67 (Fig. 3b, Supplementary Fig. 4b, c).