The antiangiogenic activity of the PEDF mutants tested with a moderate bFGF-induced neovascularization. (A) CD-1 nude mice were subcutaneously injected with 0.5 mL Matrigel containing rPEDF, plPEDF, or the mutants (all at 20 nM) in the presence or absence of bFGF (300 ng/mL). Control plugs were treated with PBS or bFGF only. After 7 days, mice were killed and the plugs were excised, fixed, sectioned, and stained. Representative fields of H&E staining of thin sections were taken using a Nikon E600 light microscope equipped with a 40 ×/0.95 objective lens and connected to a DXM1200F camera, using ACT-1 v2.62 software (Nikon). (B) Angiogenesis was quantified by counting the number of microvessels or infiltrating cells/field for 3 different cross-sectional areas and presented as a mean ± SD (n = 4). Student t test was used to analyze statistical significance of the differences between plugs treated with bFGF and plugs treated with bFGF and the various PEDF forms (*P < .01).