Angiopoietin-2 (Ang-2; also ANGPT2) is a secreted glycoprotein that regulates vascular remodeling by promoting endothelial cell survival, proliferation, and migration and destabilizing the interaction between EC and perivascular cells. Ang-2 is required for postnatal vascular remodeling, and it cooperates with Ang-1 during lymphatic vessel development. It mediates the upregulation of ICAM-1 and VCAM-1 on EC, which facilitates the adhesion of leukocytes during inflammation. Its direct interaction with Integrins promotes tumor cell invasion. Ang-2 is widely expressed during development, but it is restricted postnatally to highly angiogenic tissues such as the placenta, ovaries, and uterus. It associates into dimers, trimers, and larger multimers and binds the receptor Tie-2, with its function as an agonist or antagonist depending on its state of multimerization.