ESR1 and breast cancer: Data are normalized to cell count in each well and are shown as the mean of two biological replicates ± SD (G–I) TMR signal in T47D breast cancer WT (G), Y537S (H), or D538G (I) ERα treated for 24 hr with between 2.5 pm and 1 μM E2, 4OHT, ICI, lasofoxifene (Laso), or GDC0927.