PPI-2458 reduces proliferation of HUVEC. Human umbilical vein endothelial cells (HUVEC) were plated at 3 × 103 in 30 mm2 wells and stimulated with either (a) vascular endothelial growth factor (VEGF; 10 ng/ml) or (b) fibroblast growth factor (FGF)-2 (50 ng/ml) in 10% foetal calf serum, or were left untreated (serum-free medium). Fumagillin (10 nmol/l) and PPI-2458 (0.01 to 10 nmol/l) or 0.001% dimethyl sulfoxide as a vehicle control were added where indicated for 24 hours. Cells were pulsed with 10 μCi per well 3H-thymidine for a further 24 hours. Data are expressed as means ± standard deviation, representative of three experiments, and were analysed by one-way analysis of variance versus response in the absence of inhibitor: **P < 0.01.