IL-12p40 protein expression in PBMC. IL-12p40 protein expression is decreased in patients with MS as compared to healthy donors after TLR8 stimulation (ANOVA with Bonferroni’s correction for multiple comparisons, ** = P <0.005, n = 10 per group), but IL-12p40 protein expression was not different between patients with MS and healthy donors after stimulation with PHA (n = 10 per group). No appreciable production of IL-12p40 occurred after stimulation with TLR3, 7 or 9. Data shown are the mean ± SEM IL-12p40 protein concentration in pg/ml. MS, multiple sclerosis; PBMC, peripheral blood mononuclear cells; PHA, phytohaemagglutinin; TLR, Toll-like receptor.