Patients with mild symptoms present elevated levels of interleukin (IL)-2 and IL-12 in peripheral blood, moderate patients present an elevated level of interferon (IFN)-γ and IL-12, and severe COVID-19 patients present elevated levels of IL-6, IL-1β, IFN-α, IFN-γ, IL-12, IL-18, IL-33, IL-7, IL-8, IL-2, IL-4, IL-10, transforming growth factor (TGF)-β, TNF-α, CXCL-10/IP-10, granulocyte-colony-stimulating factor (G-CSF), monocyte chemoattractant protein 1 (MCP1), and macrophage inflammatory protein (MIP)1-α [4,5,6,7,8,9,10,11]. This evidence concerns the gene IFNG and COVID-19.