ESR1 and breast cancer: It is noteworthy, then, that E2 increases ERβ in T47D but not in MCF-7 or BT-474 [57] and the ER β:α ratio in T47D is reported to be greater than in MCF-7[53], [58] thus, suggesting that cell-specific differences in ER subtypes and other receptors may underlie differential HLA expression in breast cancer.