CD34 and diabetes mellitus: Given that 1- endogenous HDL and progenitor cell functions are impaired in ACS patients, a population characterized by a high short-term risk for recurrent ischaemic events, 2- EPCs, CD34+ progenitors and rHDL may exert rapid beneficial effects on some atherosclerotic plaque characteristics, and 3- rHDL increases EPC levels in vivo in patients with diabetes, we hypothesized that some of the beneficial effects of rHDL infusions may be mediated via an improvement of circulating EPC or CD34+ progenitor levels and function in patients with ACS.