Tie1 regulates the Tie2 agonistic role of angiopoietin-2 in human lymphatic endothelial cells

► Ang2 acts as a Tie2 agonist during lymphangiogenesis. ► Lymphatic endothelial cells express expression low levels of the Tie1 receptor. ► Association of Tie2 with Tie1 negatively regulates the Tie2-agonistic role of Ang2. ► Tie1 expression level defines whether Ang2 functions as a Tie2 agonist or antagonist. ► These findings contribute to understanding of the context-dependent Ang2.