ERBB2 and breast cancer: recently revisited data from the PAMELA trial to investigate changes in the immune compartment of HER2+ BC of patients undergoing treatment with trastuzumab and the TKi lapatinib, concluding that immune infiltration (including cytotoxic lymphocytes) is increased after two weeks of anti-HER2 treatment, in HER2-enriched subtypes that are hormone receptor negative (37).