TGFB1 and rheumatoid arthritis: ORM2 protein production was also markedly increased in the synovial fluid CD14+ cells of RA patients and in RA-FLSs after stimulation with proinflammatory stimuli, including LPS, IL-1β, and TNF-α, as well as the profibrotic cytokine TGF-β (Fig. 1g, h).