Immunoperoxidase ICC confirms hormone-induced changes in Cx43, MET, and EMT protein expression. Immunoperoxidase ICC in ESC monolayers showed Cx43 up- and down-regulation after E/P/c-induced decidualization (H+3, H+7) and withdrawal (H-3, H-7, panel A). Sequential up- and down-regulation of the epithelial marker β-catenin was associated with hormone exposure and withdrawal (panel B). Conversely, the stromal marker fibronectin showed concomitant down- and up-regulation, respectively (panel C). Magnification, ×200.