SB203580 alone inhibited TNFα and CD3/CD28 induced IL-8 production in severe asthma (SB: 5978±506 pg/ml vs. NT: 9102±606 pg/ml; p<0.0001) (Figure 2B) but the maximum inhibition of dexamethasone (10−6 M) on CD3/28 and TNFα-stimulation of IL-8 was limited (Dex (10−6 M): 7421±779 pg/ml vs. NT: 9102±606 pg/ml; p<0.05). Here, CD28 is linked to asthma.