Cytotoxicity of “single-KIR” NK-cell lines against human primary leukemic cells. Cytolysis by CD158a⁺, CD158b⁺, and CD158e⁺ NK-cell lines was tested against cells from 10 AML and CMML patients, at the effector-to-target (E/T) ratios of 10:1 (A) and 1:1 (B). For each patient, NK-cell effectors were selected according to KIR-HLA class I mismatch (■) and KIR-HLA class I match (□), as specified in Table S2. Error bars represent SD. (*P < .01, **P < .001, significant difference between killing by KIR-HLA class I–mismatched and – matched NK cells.)