angiopoietin

noun

an·​gio·​poi·​e·​tin ˌan-jē-ə-ˈpȯi-ə-tən 

: a protein that binds chiefly to a receptor on endothelial cells and promotes the maturation and stability of blood vessels

The angiopoietins have recently joined the members of the VEGF family as the only known growth factors largely specific for vascular endothelium.

—Jisun Cha and Vincent Falanga, in Transforming Growth Factor-β in Cancer Therapy …