There is a strong correlation between the proportion of KIR+CD8+ T‐cells and disease severity in several autoimmune (such as multiple sclerosis, celiac disease, systemic lupus erythematosus, and rheumatoid arthritis) and infectious diseases (COVID‐19).[36] Additionally, ex vivo expansion and reinfusion of KIR+CD8+ T‐cells may be an effective strategy for treating autoimmune diseases, including AA. This evidence concerns the gene CD8A and infectious disease.