We have not assessed directly whether NFkB is needed for IL-33 expression in our CF AECs exposed to P. aeruginosa, but in TNFα or IL-1β-stimulated myofibroblasts expressing a dominant-negative form of IkB, IL-33 expression was impaired (Kobori et al., 2010). The gene discussed is NFKB1; the disease is cystic fibrosis.