When exposure is prior to MLR, atorvastatin treatment downregulates the human proliferative response to WT (A) and GTKO (B) pAEC. hPBMC were treated with atorvastatin at different concentrations (5, 2.5, and 1.25 μM for 72h). No atorvastatin was added to the MLR. At responder:stimulator ratios of 1:10 and 1:20, atorvastatin-treated hPBMC proliferation against pIFN-γ-stimulated (250U/ml for 48h) pAEC was significantly reduced at all concentrations. Data are representative of three different experiments. Values represent the mean of triplicates (+/- SD). (*p<0.05, **p<0.01, versus vehicle only).