Anti–SDF-1 antibody prevents retinal neovascularization by HSC-derived circulating endothelial progenitors. All micrographs are merged confocal images of retinal flat mounts. Animals were perfused with a red fluorescent dye (RITC-dextran; Sigma-Aldrich) to delineate the vasculature. New blood vessels incorporate GFP⁺ HSC progeny, thereby forming areas of green/yellow fluorescence. Model control: Right, or treated, eyes from 4 representative C57BL/6.gfp animals in which retinal ischemia was induced according to our standard model. GFP⁺ progeny suggestive of astrocytes or glia are also seen incorporated outside of the vasculature. Negative control: Left, or untreated, eyes of the same 4 C57BL/6.gfp mice in which retinal ischemia was induced according to our standard model in their right eyes. Note the lack of recruitment and incorporation of transplanted gfp⁺ HSC progeny. Mock injections: Right, or treated, eyes from 4 representative C57BL/6.gfp mice in which retinal ischemia was induced according to our standard model with the added step of intravitreal injection with PBS containing an isotype control antibody to a final concentration of 1 μg/μl. Note the similar recruitment and incorporation of transplanted GFP⁺ HSC, as in model control. Anti–SDF-1, 1×, 4 injections: Right, or treated, eyes from 4 representative C57BL/6.gfp mice in which retinal ischemia was induced according to our standard model with the added step of intravitreal injection with PBS containing an anti–SDF-1 antibody to a final concentration of 1 μg/μl. Note the absence of newly formed GFP⁺ HSC in the vascular tufts.