Finally, in order to evaluate whether there are differences in the immune system status of critically ill COVID-19 and sepsis, Dong X. et al. analyzed in a total of 107 patients, neutrophil, lymphocyte, and monocyte counts, infection biomarkers (C-reactive protein, ferritin, and procalcitonin levels), lymphocyte subset counts (i.e., CD4+, CD8+, B cell, and NK cell) [213]. This evidence concerns the gene CD8A and COVID-19.