Abstract: The invention provides means and methods for determining whether a sample is derived from an individual suffering from inflammatory arthritis or from an individual at risk of suffering there from, said method comprising measuring in said sample the level of expression of at least one gene product of a gene of table A, table B or and comparing said expression level with a reference value. Further provided is a non-human animal model comprising an altered expression of a gene of table A, table B or when compared to a reference non-human animal, and use of this model as or in an arthritis model. Further provided is an in vitro assay for screening compounds for effect on a phenotype of synovial fibroblasts. The synovial fibroblast are preferably derived from a human or non-human animal suffering from inflammatory arthritis.