These differences were still significant in the comparison between groups when the frequency of the association between alleles HLA-C*08:02, HLA-C*12:03 or HLA-C*16:01 was analyzed, being more frequent in individuals with mild COVID-19 (43.8%) than in individuals with severe (8.3%; p = 0.0030; pc = 0.0330) or critical COVID-19 (16.1%; p = 0.0014; pc = 0.0154). The gene discussed is HLA-C; the disease is COVID-19.