Similar proportion of homozygosis for HLA-E*0101 (27.9%) and HLA-E*0103 (26.2%) was found in patients with mild COVID-19 (Figure 5A), whereas HLA-E*0101 homozygosis (47.4%) was 2.3- fold more frequent than HLA-E*0103 homozygosis (21.5%) in patients with severe COVID-19. The gene discussed is HLA-E; the disease is COVID-19.