No significant differences were observed for IL-17A, but we found decreased levels of IL-17B and IL-17C and increased levels of IL-17D, IL-17E, and IL-17F in patients with severe COVID-19 compared with patients with mild COVID-19, with the most significant changes being for IL-17D and IL-17F (Table 1 and Figure 1B). Here, IL17B is linked to COVID-19.