Overall, comparison of the lymphocyte numbers, types and functions between long-COVID patients (post-acute sequelae of SARS-CoV-2 infection (PASC)) and non-PASC patients revealed declined functions and reduced numbers of IFNγ−/CD107a+ and IFNγ+ CD8+ cells in PASC patients [41]. This evidence concerns the gene CD8A and long COVID-19.