Interestingly, such “exhausted” CD8+ T cells are not dysfunctional but enriched for cytotoxicity-related genes.233 Nevertheless, SARS-CoV-2-reactive CD8+ T cells have reduced cytokine production.233 Therefore, further studies are needed to fully elucidate the function of SARS-CoV-2-specific CD8+ T cells in COVID-19 patients. This evidence concerns the gene CD8A and COVID-19.