Incubation with dexamethasone before stimulation with FCS plus TGF-β resulted in inhibition of IL6 mRNA expression in ASMCs from healthy subjects and patients with nonsevere asthma (P < .001 and P < .01, respectively), with no significant effect in ASMCs from patients with severe asthma (Fig 4, A). This evidence concerns the gene TGFB1 and asthma.