TGFB1 and Hermansky-Pudlak syndrome: Transforming growth factor-beta (TGF-β) plays a critical role on the pathological process of HPS, it mediates fibroblasts proliferation, myofibroblasts differentiation, and extracellular matrix (ECM) deposition, and targeting TGF-β through different pathways can prevent HPS formation (Beanes et al., 2003; Chalmers, 2011; Lian and Li, 2016).