Effect of PF-4 on endothelial cell proliferation. LEII cells were seeded at 20,000 cells/dish. After overnight attachment, the test medium was added and cells were counted every other day for 8 days for dishes without PF-4 and at day 6 and 8 for dishes with PF-4. (○) 1% FCS; (▾) 1% FCS + 10 ng/mL FGF-2; (▪) 1% FCS + 10 ng/mL FGF-2 + 2 μg/mL PF-4. The figure depicts a representative experiment done in duplicates (data points as mean; standard deviation (SD) values: 0 < SD < 0.25).