AMD3100 and G-CSF mobilize CACs and EPCs. Peripheral blood was collected prior to treatment (baseline), 4 hours after AMD3100, or after 5 days of G-CSF treatment, and the number of (A) CACs and (B) EPCs was quantified (baseline, n = 10; AMD3100, n = 12; G-CSF, n = 7) (C) CACs were harvested from cultures of AMD3100- or G-CSF–mobilized blood MNCs and transplanted (400 000 cells) into NOD/SCID β2M mice 24 hours after induction of hind-limb ischemia. Shown is the ratio of blood flow in the ischemic versus nonischemic hind limb (G-CSF, n = 7; AMD3100, n = 12; control, n=10) (*P < .01, **P < .05, †P < .001 compared with control). (D) Individual EPC colonies from 4 donors were harvested on days 21 to 28 of culture and serially replated. Wells in which colonies grew to confluence were considered positive. Data represent mean ± SEM.