Non-responder patients have defective NK activity. NK and ADCC activities were assessed as described in legend to Fig. 2. Values of NK activity (A) were significantly lower in patients compared to normal donors at three E:T ratios. ADCC activity (B) was significantly lower in patients only at the highest E:T ratio. As expected, negligible ADCC activity was found both in patients and normal donors against the Her2-negative cell line MCF7 (C).