TGFB1 and rheumatoid arthritis: Considering the roles of the JAK/STAT signaling pathway and TGF-β1 in RA pathogenesis, and given that L-carnitine has been reported to modulate these pathways in other chronic conditions such as cardiovascular, pulmonary, and renal diseases, this study was designed to investigate whether similar effects could be observed in rheumatoid arthritis.