Specifically, the adapter protein, GRB7, and the cholesterol-binding protein, STARD3, have been shown to be coamplified and co-overexpressed as part of HER2/ERBB2 17q12 amplicon in HER2+ BC and thus they have been suggested to promote proliferation and contribute to the aggressive behaviour of HER2+ BC (32–35). This evidence concerns the gene STARD3 and breast cancer.