CD40LG and infection: The values measured on day 14 (after confirmation of the infection) showed a decrease in total serum levels of IgM (p = 0.042) and an increase of IL-33 (p = 0.009), CD40L levels (p = 0.006) and NK cells (p = 0.049) in the group of patients with severe COVID-19 versus those with moderate COVID-19 in terms of ACE2 levels (Table 1).