ERBB2 and neoplasm: It is therefore possible that trogocytosis between HER2 expressing targets and macrophage or monocyte populations also played a role in impeding tumour growth in vivo. The sensitivity of mAb-mediated ADCC and ADCP to suppression by endogenous IgG [1,162] means that targeting multiple epitopes could be a useful way of improving such responses in vivo.