CD40LG and COVID-19: Among the various theories, we know that there is a distinct antibody response in children with MIS-C compared with adults with severe COVID-19, because MIS-C predominantly generated IsgG antibodies specific for the spike (S) protein but not for the nucleocapsid (N) protein, while the adult COVID-19 cohorts had anti-S IgG, IgM, and IgA Abs, as well as anti-N IgG Abs [57].