IFNG and COVID-19: A large number of studies have shown that COVID-19 patients have raised levels of several inflammatory cytokines, including IL-1β, IL-2, IL-6, IL-10, IFN-γ, TNF-α, IFN-γ-inducible protein 10 (IP-10), granulocyte macrophage-colony stimulating factor (GM-CSF), and monocyte chemoattractant protein-1 (MCP-1), that could be identified as the indicators of disease progression [32,33,34].