HGF and neoplasm: As with EGF, the effects of IGF-1 promote tumor progression but could play a role in liver regeneration, considering that IGF-1 (as the other growth factors, HGF and EGF) exerts its action mainly via the same pathways as HGF or EGF; the effects of IGF-1 in promoting tumorigenesis are clear, but its effects on injury and regeneration are controversial.