Frequencies of PD-1+ CD8+ T cells showed increasing trends in our COVID-19+ lung tissue at baseline and their decrease with convalescence are consistent with the reported increase in circulating PD-1+ cells in COVID-19+ (Gong et al., 2020; Boppana et al., 2021; Kusnadi et al., 2021; Rha et al., 2021). This evidence concerns the gene CD8A and COVID-19.