TGFB1 and pemphigus foliaceus: These fibroblasts and myofibroblasts respond to a variety of cytokines, including CTGF, IL-6, IL-13, and IL-33, results in their abnormal activation and the induction of key fibrotic pathways including TGF-β, Wnt, and Notch, which further contribute to PF, ultimately thickening the alveolar and bronchiolar walls and leading to remodeling of the lung tissue [64].