EPCs are equipped with antioxidative enzymes. Total RNA of EPCs, HUVECs, HMVECs, and CD14⁺ monocytes (each n = 3) was isolated and the gene expression profile was assessed with the Affymetrix gene chip expression assay. (A) The mean of each group (EPCs, HUVECs, CD14⁺ cells) was calculated and used for a gene tree analysis. The color scale is shown on the right. The brightness indicates the trust. Blue color indicates low expression, red color indicates high expression. Expression of prominent clusters is marked on the right side. The mRNA expression (normalized data) of (B) SODs, (C) catalase, and (D) glutathione peroxidase mRNA expression is shown. Data are mean ± SD, n = 3. *P < .05 versus HUVECs, HMVECs, and CD14⁺ cells.