The majority of SARS-CoV-2–specific CD4+ T cells produced at least 2 cytokines (Figure 3, C and D), and IL-2+TNF-α+ SARS-CoV-2–specific CD4+ T cells were the dominant subpopulation (Supplemental Figure 4A) of the COVID-19 immune landscape. This evidence concerns the gene CD4 and COVID-19.