Immunohistochemical staining of control endometrium. Panels A, D,G,J and M are ubiquitin stained sections where brown cells are ubiquitin labelled (X400). Panels B, E, H, K and N are H&E stained sections where □ are apoptotic cells (X600). Panels C, F, I, L and O are TUNEL stained sections where ▼ are TUNEL positive cells.; Menstrual cycle phases: MP = mid proliferative; LP = late proliferative; ES = early secretory; MS = mid secretory and LS = late secretory.