ESR1 and breast cancer: IL-6 decreased the expression of E-cadherin in estrogen receptor α-positive human breast cancer cells, with constitutively ectopic IL-6-expressing MCF-7 breast cancer cells (MCF-7IL-6) exhibiting an EMT phenotype characterized by decreased expression of E-cadherin and upregulation of vimentin, N-cadherin, Snail, and Twist (108).