ESR1 and breast cancer: Recently, Yan et al[42] analyzed ER-β and its co-regulator Steroid Receptor RNA Activator Protein (SRAP) expression in tissue microarrays from a randomized, placebo-controlled trial and found that the benefit was only in the tamoxifen-treated but not in the placebo arm; therefore providing evidence that ER-β expression was predictive for response to tamoxifen inhibition of tumor growth and survival particularly in ER-α-negative premenopausal early BC.