High frequency of circulating SARS-CoV-2-specific CD4+ and CD8+ T cells in patients who recovered from COVID-19, as well as the presence of memory T cells in the convalescent phase have been extensively described in the literature and are suggested to play a key role in controlling SARS-CoV-2 initial infection, protecting from re-infection and disease progression (1–3). This evidence concerns the gene CD4 and COVID-19.