Diverse growth factors including PDGF, transforming growth factor, fibroblast growth factor, and epidermal growth factor, are main contributors to ASM remodeling, and their expression levels are directly correlated with asthma severity (Vignola et al., 1997; Puddicombe et al., 2000; Hoshino et al., 2001). This evidence concerns the gene EGF and asthma.