Previous studies both in vivo and in vitro showed that angiotensin converting enzyme (ACE) inhibitors exert antiatherogenic effects. Long term blockade of ACE significantly reduces atherosclerosis related events in patients with coronary artery disease.1 These results suggest that this class of drugs may present antiatherogenic properties; however, the mechanism for it remains to be fully elucidated. Macrophage colony stimulating factor (M-CSF, one of the major inflammatory cytokines) and transforming growth factor β (TGF-β, one of the major anti-inflammatory cytokines) have been shown to play a key role in the pathogenesis of atherosclerosis. Indeed, we and others have previously shown that plasma concentrations of M-CSF are increased while those of TGF-β are decreased in patients with coronary artery disease, and that the ratio of plasma concentrations of M-CSF and those of TGF-β well correlates with the severity of coronary atherosclerosis.2 3However, no study …