Flk-1+ cell implantation stimulated VEGF, basic FGF, HGF and IGF expression in ischemic tissue. VEGF, basic FGF, HGF and IGF synthesis in ischemic hind limb muscles was determined by real-time RT-PCR following transplantation of the Flk-1+ cells (2 × 103, 2 × 104 or 6 × 104 cells) or PBS-injection as the control(CNT). Results are expressed as the level of VEGF, basic FGF, HGF and IGF mRNA to day three control. GAPDH mRNA levels were used as the internal control. *P < 0.05 6×104 vs. CNT at each day (n = 4 in each groups). N.S. = not significant difference between groups at same day.