CD40LG and COVID-19: The cohort included a COVID-19 patient who died after receiving ECMO (COVID ECMO D), a COVID-19 patient who survived the treatment (COVID ECMO S), a COVID-19-recovered patient without ECMO support (COVID R), and one healthy control who tested negative for both a nasopharyngeal swab (NPS) and anti-Spike and anti-N IgG/IgM.