ESR1 and breast carcinoma: We found that major factor of the IHC profile variation in the ductal breast carcinoma was characterized by a strong inverse relation between the expression of hormone receptors (ER, PR, AR) along with anti-apoptotic marker BCL2, on one side, and Ki67 (proliferation) and HIF-1α (hypoxic stress, angiogenesis, see below), on the other side.