Inhibition of in vitro and in vivo angiogenesis by targeting of TAG proteins. (A) Sprout formation (± SEM) of bovine capillary ECs (BCEs) in a 3-dimensional collagen gel is inhibited by the addition of antibodies (10 μg/mL) directed against cell-surface and secreted TAGs (**P < .001). (B) Angiogenesis in the chick chorioallantoic membrane is inhibited by treatment with antibodies (10 μg/mL) directed against the indicated TAGs. Control antibody used is 9E10 anti-myc antibody (*P < .05; **P < .005).