Decreased neovascularization of Matrigel implants in Rap1b^−/− mice in the directed in vivo angiogenesis assay. Quantitation of calcein-AM fluorescent staining of cells recovered from angioreactors supplemented with 500 ng/mL VEGF (■) or 187.5 ng/mL bFGF and 62.5 ng/mL VEGF (▨) implanted in normal (WT) and Rap1b^−/− (KO) mice. Shown are means; error bars are SEM (n = 3). Asterisks indicate the datasets that were compared in a t test for statistical significance. In both instances, there was a statistically significant decrease in neovascularization of Matrigel implants in Rap1b^−/− mice (P < .05).