Although those authors did not report a higher mean level of EPCs in patients with periodontitis compared to that in healthy controls for either of the above marker combinations, they observed a higher proportion of patients with periodontitis than healthy controls among the values of EPC counts (32% versus 9% based on the CD34+/CD309+ combination and 30% versus 13% based on the CD133+/CD309+ combination). Here, CD34 is linked to periodontitis.