Thymocyte cellularity following inhibition of VEGF. Mice were treated with a continuous infusion of VEGF (50 ng/h) or PBS (controls) for a period of 4 weeks. Some animals were killed at 4 weeks for comparison purposes. Animals were then monitored for an additional 8 weeks. Total thymocytes were counted using a hemocytometer. Mean of 3 independent experiments ± SE shown. *Denotes statistical significance.