ANGPT1 and neoplasm: Tumor cell extravasation is regulated by many cytokines, including angiopoietin-1 (Ang1), a guardian of EC quiescence (Augustin et al, 2009; Huang et al, 2010), as well as angiopoietin-2 (Ang2) and vascular endothelial growth factor (VEGF), the cooperative initiator and driver of angiogenesis (Huang et al, 2010; Felcht et al, 2012).