The tumor immune microenvironment may be of particular importance in HER2-positive breast cancer as HER2 is a natural antigen and the response to HER2-targeted therapies is partly based on both the innate immune system via antibody-dependent cell cytotoxicity (ADCC) as the adaptive immune system, by means of NK-cell activation [11, 12]. The gene discussed is ERBB2; the disease is neoplasm.