ERBB2 and breast cancer: Our results on cooperation between disruption of cell polarity and activation of ErbB2 are consistent with recent studies in Zebrafish where loss of Lgl2 cooperated with ErbB2 to induce invasive behavior [33] and in human breast cancer cells where overexpression of 14-3-3ζ,a component of polarity complexes, cooperated with ErbB2 to induce EMT and invasion [12].