Phenotypic fibroblast to myofibroblast transition in asthma is a process characterized by an increased number of myofibroblasts in fibrotic lung tissue as a result of EMT, and activated by several factors, including TGF-β, interleukins (e.g., TNF-α, IL-4, IL-5, IL-11, IL-13) and chemokines (e.g., periostin, osteopontin, eotaxin), which contribute to bronchial remodeling [108]. This evidence concerns the gene IL4 and asthma.