These mAb can also activate both innate and adaptive immune systems, inducing antibody-dependent cytotoxic cellular (ADCC) killing of HER2-overexpressing cells via NK cells; they can also elicit an adaptive immune response based on HER2 presentation by MHC-I molecules (Figure 1) to activate the anti-tumor activity of CTL and reduce Treg cells in tumor [22]. This evidence concerns the gene ERBB2 and neoplasm.