MMP1 and rheumatoid arthritis: In our present study, given the strong correlation of 14-3-3η with MMP-1 and MMP-3 in synovial fluid and serum [5], we sought to advance the understanding of the role of 14-3-3η in RA by assessing whether 14-3-3η (1) possesses extracellular ligand properties leading to activation of MAPK, (2) induces mediators of inflammation and joint destruction and (3) contributes prognostic information in addition to clinical and serological measures used in the management of RA.