Yang et al.20found that the expression of PD‐1 was upregulated in CD4+ T cells of COVID‐19 patients. In a study conducted by Diao et al.,17 PD‐1 expression in CD4+ T cells was also upregulated in COVID‐19 patients and influenced by disease severity. In our experience, PD‐1 overexpression in CD4+ T cells of COVID‐19 patients was not observed. The gene discussed is CD4; the disease is COVID-19.