Our results demonstrated that half the patients hospitalized for COVID-19 had developed IgM specifically directed against M (16/30 of ICU and 17/31 of non-ICU were responders), N (18/30 of ICU and 17/31 of non-ICU), and S1 antigens (15/30 of ICU and 14/31 of non-ICU) when compared to HDs (Fig. 1A). This evidence concerns the gene CD40LG and COVID-19.