Therefore, we sought to determine if the tumor suppressor gene product retinoblastoma (Rb), a negative regulator of cell cycle activity, inhibits IL-6, MMP-1, and p38 in RA synovial fibroblasts.
The availability of potent and selective p38 mitogen activated protein kinase inhibitors provide a means in further dissecting the pathways implicated in cytokine production, which in turn maintain the chronicity of RA.