There is less TGFβ and more TNFα signaling in RA to combine with IL-17A, which results in higher MMP13-driven proteoglycan destruction.179,336 Similarly, how does IL-13 promote ECM fibroblast differentiation and fibrosis either alone or in combination with TGFβ in some models, while also driving fibroblast activation in TLS formation in a model of SS? Here, TGFB1 is linked to rheumatoid arthritis.