TGFB1 and systemic sclerosis: Ly (2020) has recently proven that miR-145 mediates α-smooth muscle actin (α-SMA) myofibroblast differentiation through downregulation of transcription factor Kruppel-like factor 4 (KLF4) in TGF-β1-stimulated dermal fibroblasts and SSc fibroblasts.