Requirement for membrane CD146 expression in angiogenic effects of rh-sCD146. (A) Effect of CD146 siRNA on rh-sCD146–mediated effects on late EPC capacity to generate pseudocapillaries in Matrigel, proliferation, and migration. Results are mean values of 4 different experiments. (B) Effect of CD146 siRNA on rh-sCD146–mediated induction of uPA. A representative experiment and the mean values of 3 different experiments are shown. *P < .05, *P < .01, ***P < .001, experimental versus control.