Given the role of KIRs in the immune response and their extensive genomic diversity, it is conceivable that KIR gene variation and KIR–HLA association affect resistance and susceptibility to the pathogenesis of many diseases, such as infectious diseases and autoimmune/inflammatory disorders, through modulation of NK activation, cytotoxicity and cytokine release [15]. This evidence concerns the gene KIR3DL1 and infectious disease.