Mechanisms involved in atorvastatin-induced decay-accelerating factor expression. Human umbilical vein endothelial cells (HUVEC) were cultured for 48 hours under hypoxia (1% O2) and were treated with atorvastatin (At) (0.5 μM) in the presence or absence of mevalonate (200 μM), NG-monomethyl-L-arginine (L-NMMA) (500 μM), NG-nitro-L-arginine methyl ester (L-NAME) (100 μM) and geranylgeraniol (GGOH) (20 μM). Endothelial cell CD59 expression was measured by flow cytometry using the mAb BRIC 229. Results are expressed as the percentage increase in relative fluorescence intensity above the hypoxic control (US) (n = 4). *P < 0.5, **P < 0.01 compared with untreated controls.