(A) NK cell activating and inhibitory receptors and their ligands. (B) KIR gene organization. KIR haplotype illustrating centromeric and telomeric KIR gene motifs. BAT-3, HLA-B–associated transcript 3; H60, histocompatibility 60; hsp60, heat shock protein 60; HSPG, heparin sulfate proteoglycans; MIC, MHC class I chain-related gene; VH, viral hemagglutinin; ULBP, UL16 binding protein.⁸³