The binding of NLK to HER2 induces HER2 phosphorylation, metalloprotease-mediated ectodomain shedding, and the activation of PI3K and MAPK signaling, resulting in the ablation of the inhibitory effect of trastuzumab on cell growth in breast cancer cells (Kho et al., 2013). This evidence concerns the gene ERBB2 and breast cancer.