“…[2] Even more, the circulating EPC levels are influenced by several factors: circadian rhythms, [3] different concentrations of cytokines or growth factors in blood or pathophysiological status of the patients. [4,5] In patients with acute coronary syndrome, compared with patients with stable angina following elective coronary angioplasty, a more pronounced increment of EPC counts has been described. [6] However, this increment could be related with higher pro-inflammatory cytokine levels or with an increase in circulating endothelial cells, suggesting an inflammatory response or vascular damage, respectively.…”