This finding is also supported by the results of a recent study [36] illustrating the simultaneous and dramatic downregulation of ERBB2, GRB7, PERLD1(PGAP3), and STARD3 (all of which reside in the ERBB2 amplicon) by β-catenin depletion in breast cancer cells, which provides evidence that these genes are likely co-regulated. This evidence concerns the gene GRB7 and breast cancer.