IFT88 iEC-KO mice show defects in vascular expansion and density. Ift88^fl/fl;Pdgfb-iCre-ERT2-Egfp^+/wt (IFT88 iEC-KO) and littermate mice (control) were injected with tamoxifen at P1 and P3 and eyes collected at P6. (A) Representative images of retinal wholemounts stained with Isolectin B4 (IB4, black; green circles represent the radial expansion in control mice) and quantification of the radial expansion of the vascular plexus in IFT88 iEC-KO mice and littermate controls (WT, n = 9; KO, n = 12; median ± IQ; two-sided Wilcoxon test). (B) Representative images (black, IB4) and quantification of vascular density of the plexus in IFT88 iEC-KO mice and littermate controls (expressed as vascularized area normalized to control situation; WT, n = 5; KO, n = 9; median ± IQ; two-sided Wilcoxon test). (C) Representative images (black, IB4) and quantification of the number of sprouting cells (orange arrowheads) in IFT88 iEC-KO mice and littermate controls (WT, n = 6; KO, n = 5; median ± IQ; two-sided Wilcoxon test). **, P < 0.01; ***, P < 0.001.