RISER augments Ab-induced NK cell-mediated ADCC. NK cells from five healthy donors (n = 5) were incubated with 51Cr-labeled autologous EBV-transformed B cells at a 10:1 E:T ratio in the presence of rituximab (A) or mutant anti-CD19 Ab (Xencor) (B) or in the absence (□) or presence (■) of NK cell RISER Abs combination binding NKG2A, CD94, KIR3DL1, KIR2DL1, KIR2DL3, KIR2DL2, and KIR2DS2. Cytotoxicity was calculated using a 4-h 51Cr release assay. All Abs were used at 1 μg/ml concentration. Results shown are mean ± SD of one representative experiment of at least three independent experiments.