Rheumatoid Arthritis (RA) is one of the most prevalent inflammatory joint diseases in the developed world and 1% of the UK population is affected. Arthritis pathology is complex and is driven by pro-inflammatory cytokines such as Interleukin 1 (IL-1) and Tumour Necrosis Factor-a. Biologics which target these cytokines have proved successful in the clinic although not all patients respond to these treatments suggesting that other pro-inflammatory cytokines are involved. Research has suggested a role for Oncostatin M (OSM) in the pathology of arthritis and studies have suggested OSM can synergise with IL-1 to promote cartilage catabolism.