Sun M, Rethi B, Krishnamurthy A, et al. - Fibroblast-like synoviocytes (FLS, add to an inflammatory stroma that promotes and amplifies tissue-specific immune activation through the release of different cytokines and has the capability to grow into the cartilage surface and create an erosive interface by producing tissue remodeling proteases, like matrix metalloproteinases, and cathepsins) were separated from the synovial membrane of individuals with RA in order to scrutinize supplementary mechanisms by which anti-citrullinated protein/peptide antibodies (ACPAs, exist former to the onset of RA) might add to the development of joint pathology. It was suggested that in the presence of a certain preexisting ACPA repertoire, transient synovial insults might lead to an ACPA-mediated rise of FLS migration.