TNF and skin disorder: Excessive exposure to UVB radiation typically leads to skin disorders by stimulating inflammatory factors, such as IL-1, IL-6, IL-7, IL-8, IL-12, IL-15, TNF-α, monocyte chemoattractant protein (MCP)-1, and granulocyte-macrophage colony-stimulating factor (GM-CSF), in keratinocytes in the skin24,25.