Effect of LPS on HO-1 mRNA expression in PBMCs from BD patients. Expression of (a) heme oxygenase (HO)-1 and (b) tumor necrosis factor (TNF) mRNA in peripheral blood mononuclear cells (PBMCs) from patients with Behçet's disease (BD; n = 18). Values presented are mean and standard error of the mean (SEM) change, regarding 1 to be the value of untreated cells. #P < 0.001, as determined using paired t-test. (c) Relationship of endogenous Toll-like receptor (TLR)4 mRNA with gap in HO-1 mRNA between PBMCs subjected to 6 hours of treatment with lipopolysaccharide (LPS) and untreated PBMCs (ΔHO-1). P = 0.02, r = 0.53, as determined by regression analysis. AU, arbitrary unit; GAPDH, glyceraldehyde-3-phosphate dehydrogenase.