IFNG and COVID-19: We enrolled 150 COVID-19 patients, who were classified by their systemic TNF and IFN-γ levels (high (H) or normal–low (N-L)) as TNFHIFNγH, TNFHIFNγN-L, TNFN-LIFNγH, and TNFN-LIFNγN-L.