It is reported that a SARS-CoV-2 peptide S816-830, which is relatively conserved in common cold HCoVs, could activate CD4+ T cells in 20% of SARS-CoV-2–unexposed donors and more infected or vaccinated donors, and thus, the authors concluded that the cross-reactive CD4+ T cells could be protective in COVID-19 [64]. The gene discussed is CD4; the disease is COVID-19.