BOECs from patients with VWD show increased in vitro angiogenesis, proliferation, and migration. (A) Representative images of BOECs from a healthy control (top, far left) and a VWD patient (bottom, far left). Colonies appeared after 7-22 days in culture (size bar = 200 μm). BOECs were stained for VE-cadherin, ICAM-2, and CD45. Nuclei were stained with TO-PRO 3 (Invitrogen). Size bar = 20 μm. (B) Secretion of VWF (μg/mL) from cultured BOECs after 48 hours. (C) BOEC were seeded onto Matrigel for 24 hours and capillary network formation was quantified by measuring total tube length in micrometers. Size bar = 200 μm. (D) Proliferation of BOECs cultured with 100 ng/mL VEGF for 96 hours relative to unstimulated controls. (E) Migration velocity of cells at the periphery of endothelial colony prior to the first passage. Each patient is identified with a unique symbol (see supplemental Table 1 for code and information on VWD patients). Error bars indicate mean ± SEM. *P < .05; **P < .01 (Student t test).