Absence of NK-cell education impairment after allogeneic HSCT. The percentages of CD107a⁺ cells in specific NK-cell subsets were determined after incubation with K562 targets. (A) The NKG2A⁻KIR⁻, NKG2A⁻KIR⁺, NKG2A⁺KIR⁻, and NKG2A⁺KIR⁺ subsets were evaluated in 16 post-HSCT samples. (B-D) The monoKIR subsets in 34 post-HSCT samples from recipients of HLA-C group–matched transplants (C1/C1→C1/C1: n = 13, C1/C2→C1/C2: n = 10, C2/C2→C2/C2: n = 11) were studied. (B) Representative examples are shown. (C) In homozygous recipients, monoKIR NK-cell responsiveness was compared between cells expressing a receptor for self-HLA (CD158b in C1/C1 subjects, CD158a in C2/C2 subjects) and for nonself-HLA (CD158a in C1/C1 subjects, CD158b in C2/C2 subjects). (D) The responsiveness of (left) CD158a monoKIR and (right) CD158b monoKIR NK cells was compared between recipients as a function of HLA-C genotype. When several samples were available for the same recipient, only the latest was included in the analysis. All dot plots were gated on total NK cells. Horizontal bars indicate the medians. **P < .01; ***P < .001.