The importance of this role is highlighted by immunogenetics studies in which carriage of KIR genes together with the genes encoding their ligands has been statistically associated with control of viral infection, increased survival following hematopoietic cell transplant in leukaemia patients, risk of autoimmunity and probability of reproductive success (Hiby et al. 2004, 2014; Jiang et al. 2013; Ruggeri et al. 1999; Traherne et al. 2016). Here, KIR3DL1 is linked to viral infectious disease.