TNF and fibrosis: Fibrosis is a well-established pathological process, seen in many chronic diseases, usually with an inflammatory component.34 Drivers include inflammatory cytokines (IL [interleukin]-1β, IL-6, and TNF [tumor necrosis factor]-α), growth factors (TGF [transforming growth factor]-β1 and PDGF [platelet-derived growth factor]), and matrix polysaccharides (hyaluronan and chondroitin).