Consistent with a previous study, we found lymphocyte, CD4+ T cell, CD8+ T cell, NK cell, and B cell counts to be negatively correlated to the severity of COVID-19, suggesting that immune suppression could be more likely found in severe patients and SARS-CoV-2 may directly or indirectly damage the lymphocytes or NK cells and thus further aggravate the disease progression17,18. The gene discussed is CD8A; the disease is COVID-19.