The production of cytokines in COVID-19 patients and CD4+ T lymphocytes isolated from SARS-CoV-2-vaccinated subjects stimulated with a peptide pool predominantly expressed IL-2 and IFN-γ, whereas IL-17A, IL-4, and IL-10 were less frequent and not significant [30,31,32,33]. The gene discussed is CD4; the disease is COVID-19.