TNF and encephalitis: Previous studies have found that IL-6, IL-1β, IL-8, tumor necrosis factor-alpha (TNF-α), monocyte chemotactic protein-1 (MCP-1), and granulocyte-macrophage colony-stimulating factor (GM-CSF) was highly elevated either in serum or CSF of patients with COVID-19 related encephalitis (1, 14, 15).