Inhibition of TRAF6 signaling on the chick CAM inhibits LPS- but not bFGF-induced angiogenesis. Avian retroviral producer lines were used to infect the proliferating cells (mainly endothelial) on the chick CAM with either empty vector (CK) or a dominant-negative TRAF6 (CK-TRAF6-C). (A) A representative CAM showing LPS-induced angiogenesis following infection of the CAM by empty vector (left panel) or TRAF6-C (right panel). The arrows point to the corners of the mesh on which the retroviral producer lines are seeded. (B) Quantitation of vessel number entering the mesh following retroviral infection and stimulation with bFGF (30 ng/mL) or LPS (10 ng/mL). Results shown are the number of vessels entering the mesh perimeter over baseline control (medium only). The number of experiments for each condition is shown over the bars. Results shown are the mean + SEM. *P ≤ .05.