The clinical success of these new therapies is attributed to the combined effect of the HER2 inhibitor trastuzumab linked to a cytotoxic agent, which, once released in the cell, can diffuse into the adjacent neighboring cells and induce non-antigen dependent cytotoxicity, having a broader effect on both HER2-overexpressing and non-overexpressing tumor cells [12]. This evidence concerns the gene ERBB2 and neoplasm.