A significantly lower incidence of the low-affinity KIR3DL1+HLA-Bw4 T80+ combination (18.5 vs. 27.7%, p = 0.03, OR = 0.6, CI = 0.37–1.0) was observed in COVID-19 patients than the general population. The gene discussed is KIR3DL1; the disease is COVID-19.