SARS-CoV-2-specific CD4+ and CD8+ T cells are found in peripheral blood from COVID-19 patients in the first two weeks after symptom onset, and the majority of these CD4+ T cells exhibit a central memory phenotype with a dominant production of Th1 cytokines, while CD8+ T cells have a more effector phenotype with high levels of perforin expression [459]. This evidence concerns the gene CD4 and COVID-19.