TGFB1 and systemic sclerosis: Besides, miR-196a/b, including miR-196a and miR-196b-5p, which block the TGF-β-mediated synthesis of Col-1α2 in dermal fibroblasts of bleomycin-induced SSc mouse models, may be one of the mechanisms by which MSC-EVs inhibit skin fibrosis in SSc [82, 83].