Some highly innovative studies reported that, in RA, TGF-β is up-regulated by transglutaminase 2 (TG2), an enzyme that regulates ECM composition and degradation and, consequently, EMT through the activation of the transcription factors Snail/Slug, Twist, Zeb, and E47 [39]. Here, TGFB1 is linked to rheumatoid arthritis.