Fig. 1.

Effect of lasofoxifene on the progression of primary tumors expressing WT and mutant ERα. a Representative in vivo luminescence images of mice bearing tumors expressing MCF7 WT, Y537S, and D538G ERα at day 56 after treatment initiation. b Total photon flux of luminescence signals measured by in vivo imaging for tumors expressing MCF7 WT, Y537S, and D538G ERα over time (n = 8–10). c Average weight of mammary glands at sacrifice (n = 8–10 glands). *p < 0.05, **p < 0.005, ***p < 0.0005, ****p < 0.0001 by Student’s t-test. F, fulvestrant; L1, L5, and L10, lasofoxifene at 1, 5, and 10 mg/kg; SEM, standard error of the mean; V, vehicle