ESR1 and breast cancer: We directly compared the gene expression changes observed after OvX with those following neoadjuvant AI treatment in ER + postmenopausal women with early breast cancer that we have previously reported.9 We found that changes in the overall gene expression after OvX strongly correlated (slope 0.55, Spearman rho = 0.55, p < 1e-04; Supplementary Figure 4A) with those reported after an AI.9 There were 432 genes (350 down, 82 up) whose expression was significantly affected by both OvX and AI (FDR < 1%).