CDH1 and breast cancer: To corroborate that our studies in MCF7 cells showing that β2-chimaerin decreases E-cadherin can be extrapolated to this model, we first confirmed that β2-chimaerin also downregulates E-cadherin protein levels in BT474 cells, a breast cancer epithelial cell line that overexpresses the ErbB2 receptor (Supplementary Figure S1 and S2).