HS, hypertrophic scar; BOO, bladder outlet obstruction; OSF, oral submucous fibrosis; TGF-β, transforming growth factor-β; Smad2/3, drosophila mothers against decapentaplegic protein 2/3; PI3K, phosphatidylinositol 3-kinase; Akt, protein kinase B; MAPK, mitogen-activated protein kinase; JAK2, Janus kinase 2; STAT3, signal transducer and activator of transcription 3; ROCK, rho-associated coiled-coil containing kinase. Here, SMAD2 is linked to oral submucous fibrosis.