ERBB2 and neoplasm: All these findings demonstrate that, in the NEO patients, both the FcγRIIIA 158F and FcγRIIA 131R carrier genotypes can efficiently induce ADCC also at low E:T ratios and that different HER-2 expression levels on tumor target cells can affect the intensity of ADCC triggered by the FcγRIIIA 158F and 131R carriers.