TGFB1 and rheumatoid arthritis: TNF-α impairs the differentiation and function of TGF-β–induced Tregs in RA through the Akt and Smad3 signaling pathways, and the specific TNF-α inhibitor, infliximab, has been reported to increase the number of peripheral Tregs, especially through the generation of TGF-β–induced Tregs in RA patients (Salomon, 2021).