PDF file, 320KB, Supplementary Figures 1-9 Supplementary Figure 1: Expression levels of aromatase in our cell lines and aromatase activity assay Supplementary Figure 2: Proliferation of Aro and LetR in response to treatment Supplementary Figure 3: Kaplan Meier estimates of disease free survival in the entire ER positive population Supplementary Figure 4:Interactions between ERalpha and AIB1 in letrozole sensitive Aro cells Supplementary Figure 5: Analysis of protein levels in Anastrozole resistant cell line (ANAR) Supplementary Figure 6: ChiP showing recruitment of ERalpha and AIB1 to distal region promoters Supplementary Figure 7: Basal protein levels of Myc and cyclinD1 protein and basal mRNA levels of pS2 Supplementary Figure 8:Effect of Lapatinib treatment on pS2 and Myc mRNA levels Supplementary Figure 9: Pathway analysis of ERalpha-AIB1 target genes.