Importantly, TGF-β, as a profibrotic cytokine, can promote EMT, ECM accumulation, and fibroblast proliferation and differentiation to myofibroblasts to participate in PF, which may be mediated by the Smad2/3 signaling pathway (Kolahian et al., 2016; Walton et al., 2017; Lederer and Martinez, 2018). This evidence concerns the gene TGFB1 and pemphigus foliaceus.