NOS3 and hepatocellular carcinoma: Ang2 is an angiogenic factor that, through its cooperation with the vascular endothelial growth factor (VEGF) pathway, plays a crucial role in angiogenic remodeling and is closely related to the development and prognosis of HCC [57, 58] via the up-regulation of protein kinase B (AKT) endothelial nitric oxide synthase (eNOs) as well as AKT/β-catenin signaling pathways [59].