TGF-β is a regulatory protein family involved in cell proliferation and differentiation and may show different functions in different tissues In human hair follicles, the presence of TGF-β1 and 2 triggers the transition from the anagen phase to the catagen, with TGF-β1 playing a significant role in the development of androgenetic alopecia [25]. This evidence concerns the gene TGFB1 and androgenetic alopecia.