- Estrogen receptor beta, but not estrogen receptor alpha, is present in the vascular endothelium of the human and nonhuman primate endometrium. Critchley, H.O., Brenner, R.M., Henderson, T.A., Williams, K., Nayak, N.R., Slayden, O.D., Millar, M.R., Saunders, P.T. J. Clin. Endocrinol. Metab. (2001)