IFNG and COVID-19: By comparison with health individuals, Th1 cells present in COVID-19 patients characteristically expressed CXCR3 and CCR6, as well as transcripts encoding anti-viral cytokines and chemokines, including CD154, IFN-γ, IL-2 and TNF 92, while their expression of IFN-γ, IL-2 was lower than influenza-reactive Th1 cells 93.