Figure 1. Representative KIR A and B haplotypes illustrate centromeric (Cen-A and Cen-B) and telomeric (Tel-A and Tel-B) gene regions, with the HLA-C ligands (C1 and C2) depicted above their cognate receptors.

In addition, KIR2DL2 also binds subsets of C2 allotypes (54), and KIR2DS4 binds some C1 and C2 allotypes (63). A KIR2DS5 locus may also be found in the Cen-B region, but this is seen infrequently in the white British population. Similarly, KIR2DS3 is most often associated with the KIR2DL5B locus in the Cen-B region, as shown here, but may occasionally occur in the Tel-B region (18).