PDGF-BB promotes vascular development and sprouting angiogenesis via PDGF-Β. Here an embryonic body of PDGFRβ^–/– origin was placed in a 3-D collagen gel, cultured with VEGF-A165 and stained for CD31 (red), α-smooth muscle actin (green), and cell nuclei (blue). See the related article by Rolny et al, beginning on page 1877.