Indeed, in a study in uninfected individuals, Ng et al54 detected IgG antibodies against the S2 subunit of SARS‐CoV‐2, whereas COVID‐19 patients had high titres of Ig of all classes (IgG, IgA and IgM) directed against both the S1 and S2 subunits. This evidence concerns the gene CD40LG and COVID-19.