TGFB1 and systemic sclerosis: miR-21 is upregulated, and miR-29a is downregulated in dermal fibroblasts from systemic sclerosis patients compared to non-diseased controls; furthermore, miR-21 is upregulated when dermal fibroblasts are treated with TGF-β, and TGF-β and miR-21 synergistically induce collagen production (56).