TNF and rheumatoid arthritis: These include: the biologic anti-cytokine therapies directed towards IL-1α, TNFα or IL-6 that are successful rheumatoid arthritis therapies [30]; p38 mitogen activated protein kinases (MAPK) pathway inhibitors, protective in a rat model of OA [31,32] and in explant culture [33]; statins that inhibit cartilage breakdown by reducing protein prenylation [34,35]; and sulfazalazine that can inhibit collagenase production by inhibiting the NFkB pathway in cartilage explant models [36].