TGFB1 and pterygium: However, the role of numerous growth factors in pterygium pathogenesis has also been described, such as heparin-binding epithelial growth factor (HB-EGF) [18], vascular endothelial growth factor (VEGF) [19], transforming growth factor β (TGF-β), platelet-derived growth factor (PDGF), and basic fibroblast growth factor (bFGF) [20].