Subjects with PCOS had a reduced number, mean±SEM, of circulating CD34+133+ VPCs (317.5±51.0 vs. 558.3±101.2, p = 0.03) and impaired in vitro tube formation (completed tube area 1.0±0.06 vs. 1.2±0.05×106 μm2 p = 0.02). This evidence concerns the gene CD34 and polycystic ovary syndrome.