Fig. 7. Puromycin-selected endothelial cells are incorporated into neovessels in vivo. (A) Localization of EGFP⁺ in cryo-sections of co-injected (left) and control (right) tumors. EGFP⁺ cells are incorporated into the tumor neovasculature, as visualized by CD31 staining. Arrows indicate EGFP⁺CD31⁺ cells present in sections of `co-injected' tumors. Note that the extent of neovascularization was similar in both types of tumors, but that the EGFP expression was observed only in co-injected tumors. (B) Analysis of -SMA expression in tumors. Tumor sections were co-stained for -SMA (red) and CD31 (green). Bar, 100 µM.