Statistical analysis of for HLA-DQ & HLA-DP & IFNλ4 in the three study groups clarified that the presence of HLA-DQ rs7453920A, HLA-DP rs3077G, IFNλ4rs73555604C in the same person increased the risk of severe COVID-19 manifestation markedly that may reach hundred times (Table 4). This evidence concerns the gene IFNL4 and COVID-19.