Till date, the existing PF models include use of chemical agents such as bleomycin, asbestos, silica, profibrotic cytokines such as TGF-β, TNF-α, IL-1β, IL-13, acid-instillation, radiation, age-induced and inducing transgene such as mutant surfactant protein C gene (SFTPC) (207, 208). This evidence concerns the gene IL13 and pemphigus foliaceus.