Concerning COVID-19 T8 lymphocytes, we noticed a differentiation (decrease in naïve and central memory cells contrasting with an increase in effector memory cells, Figures 1E–G), activation (CD38+, CD38hi, and HLA-DR+CD38+, Figures 1H–J), and exhaustion (PD-1+, Figure 1K). Here, PDCD1 is linked to COVID-19.