TGFB1 and asthma: A reduction in IL-6 release induced by FCS plus TGF-β stimulation in ASMCs from healthy subjects (P < .001) and those from patients with severe asthma (P < .01) was observed, as previously described (see Fig E2, A and B, in this article's Online Repository at www.jacionline.org).3, 8 Furthermore, to demonstrate that electroporation had no adverse effect on cellular viability, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays were performed both before (see Fig E2, C and D) and after (see Fig E2, E and F) stimulation with FCS plus TGF-β.