KDR and migraine disorder: The EPC counts in patients with comorbid migraine (n = 4) did not differ from that in patients without comorbid migraine (n = 20) (CD34+KDR+ cells (0.007 ± 0.006% vs. 0.009 ± 0.006%, p = 0.751), KDR+CD133+ cells (0.027 ± 0.010% vs. 0.032 ± 0.015%, p = 0.642), CD34+CD133+ EPCs (0.042 ± 0.007% vs. 0.045 ± 0.030%, p = 0.781)).