These innate immunological differences can be associated with differences in the NK or NKT cells and more precisely with the balance of signaling through their activating versus inhibitory receptors such as NKG2A/NKG2C/NKG2D or KIR receptors, which like certain HLA alleles are highly patient-specific and have already been linked to resistance/susceptibility to infectious agents, autoimmune diseases, and cancer [81–86]. The gene discussed is KLRK1; the disease is cancer.