ACTA1 and systemic sclerosis: While many in vitro experiments rely on TGFβ1 to promote fibrosis, TGFβ2 has been shown to mediate cardiac fibroblast differentiation into myofibroblasts [67] and to be epigenetically modified in SSc [68], while TGFβ3 has been reported to increase collagen I deposition and αSMA expression in dermal fibroblasts [69].