Specifically, in cohort 1 we identified SNPs in the following genes, Killer Cell Immunoglobulin like Receptor, Two Ig Domains and Long Cytoplasmic Tail 1 (KIR2DL1) that is an inhibitory receptor upregulated in COVID-19 patients with acute respiratory distress reflecting reduced antiviral activity of natural killer cells in them [56]. This evidence concerns the gene KIR2DL1 and COVID-19.