Therefore, in cells depleted for a given RTK, as is found in triple-negative breast cancer (e.g., in MDA-MB-468 cells, which do not express Her2; Fig. 4d), proliferative or metastatic signalling could be driven by the uncontrolled impact of monomeric Grb2-mediated Shp2 activation. Here, ERBB2 is linked to triple-negative breast carcinoma.