Schematic diagram of the effect of Ang1 on endothelial and hematopoietic differentiation. CD41⁺ cells derived from Flk-1⁺ MPCs differentiate further into either the endothelial or the hematopoietic lineage. Ang1 potentiates EC differentiation via Ang1/Tie2 signaling, and its mechanisms are: (1) modulating CD41⁺ cells to differentiate into the endothelial lineage rather than the hematopoietic lineage, and (2) promoting EC proliferation and survival during differentiation.