ERBB2 and breast carcinoma: Integrin α6β4 was shown to be involved in ErbB2-driven cell proliferation and invasiveness in breast cancer cell lines [43], and in Neu-β4-WT mice the β4–ErbB2 complex enhances activation of STAT3, leading to deregulation of epithelial adhesion, loss of cell polarity, activation of c-Jun and hyperproliferative activity [44].