KIR repertoires are shaped by HLA class I–dependent mechanisms. The repertoire of donors with group A/A haplotypes (A) and group B/B haplotypes (B) is shown for C1/C1 (□) versus C2/C2 (■) donors. HLA class I ligand and haplotype group distribution of samples is shown in Table 2. Designation of clonotypes does not include cross-reactive stimulatory KIR. KIR⁻NKG2A⁻ refers to NK cells expressing no inhibitory receptors. Statistical significance was determined by 2-tailed t test at *P < .05, **P < .01, ***P < .001. SD is indicated by error bar.