IHC analysis of the primary tumor tissues showed that estrogen promoted the expression of CD49f, ERα, NOTCH1, and Vimentin, and that the expression of E-cadherin was decreased; the changes induced by E2 were significantly inhibited by tamoxifen (Additional file 4: Figure S4), and the Western blot results showed the same trends (Fig. 5g). This evidence concerns the gene ESR1 and neoplasm.