(A) Violin plots showing the gene expression of growth factors among the 11 clusters of CD11b⁺F4/80⁺ cells. (B) tSNE plot showing the gene expression of Vegfa and Igf1 among the 11 clusters of CD11b⁺F4/80⁺ cells. (C) Representative immunofluorescence images of IGF1 (red), microglia/macrophages (F4/80, green), and vessel (isolectin B4, blue) in whole-mount retinas of RA and OIR mice at P17. NC, negative controls; stained with isotype IgG of IGF1 and F4/80 antibody. Scale bar: (first, second, and fourth rows) and 20 μm (third and fifth rows). (D) The fluorescence intensity of IGF1 staining was calculated by ImageJ software (5 images × 3 regions were obtained from n = 5 retinas of each group). Data are mean ± SEM. ***P < 0.001 versus RA by Student’s t test. (E) Retinal microglia were isolated and cultured from P17 OIR mice or control (RA) mice. Culture supernatants were analyzed for IGF1 protein content by ELISA (n = 6). Data are mean ± SEM. ***P < 0.001 versus RA by Student’s t test. (F) qPCR analysis of mRNA expression of Pkm2 and Igf1 in myeloid cells isolated from RA or OIR retinas of Pkm2^WT or Pkm2^Mye-KO mice at P17 using CD11b antibody–conjugated magnetic beads (n = 4). Data are presented as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001. Statistical significance was determined by 1-way ANOVA followed by the Bonferroni test. (G) Schematic illustration of coculture of aortic/choroidal explants and retinal microglia. (H) Mouse retinal microglia (MRM) were transfected with siRNAs targeting mouse Igf1 (siIgf1) or with a nontargeting negative control (siCtrl). Forty-eight hours after transfection, MRM were harvested and cocultured with aortic ring and choroidal explants in transwells. Representative images of sprouting aortic rings and choroids were captured with a fluorescence confocal microscope. (I) Sprouting areas were quantified in Figure 6H. n = 8. *P < 0.05, ***P < 0.001. Data are mean ± SEM. Statistical significance was determined by 1-way ANOVA followed by the Bonferroni test.