CD16 uses additional pathways for killing. PBMCs were incubated with inhibitors for 1 hour prior to the addition of target P815 cells with the indicated mAb. (A) No inhibitor, (B) PI3K inhibitor wortmannin, and (C) MEK inhibitor PD98059. (D) The assay was titrated to obtain similar cytotoxicity by CD16 and NKp30, and examined again with no inhibitor, wortmannin (Wort), PD98059 (PD), p56lck inhibitor damnacanthal (Dam), or JNK inhibitor SP600125 (SP). Lysis assays were performed as before. Representative data of 1 of at least 3 experiments is shown. Error bars indicate standard deviation.