CD40LG and respiratory tract infectious disorder: This indicates that anti‐ACE2 IgM is unique for the SARS‐CoV‐2 virus, and that autoantibodies against CD209 and CD209L could be observed in other serious respiratory infections as these proteins act as receptors for other viruses as well (e.g. Ebolavirus, hepatitis C virus, human cytomegalovirus/HHV‐5 and influenza virus).43