TNF and infection: Gene expression of multiple cytokines is raised in the conjunctiva during each stage of disease: IL-1β, TGF-β, TNF-α, IFN-γ, IL-2, IL-4, IL-12 p40 during infection; IL-1β, TGF-β, TNF-α, IL-17A, CCL18 and CXCL5 during active disease, and IL-1β, TGF-β and TNF-α in scarring [6–9].