IL17A and COVID-19: Development of sarcoidosis following COVID-19 infection has also been reported.63,64 Although the causes of sarcoidosis are not fully understood, evidence suggests that an aberrant TH1 response together with cytokines such as IL–2, IL–12, IL–17, IL–22, IFN–γ, and tumor necrosis factor–α may contribute to sarcoidal granuloma formation.65,66 However, we believe that our findings regarding this should be interpreted with caution because we had only a small number of incident cases in the COVID-19 group.