These studies show the feasibility and efficacy of PS341 (Velcade/Bortezomib) delivery in vivo, and combined with our data suggest that a therapeutic effect of proteasome inhibitors in CF pathology can be expected at two interrelated levels, first functional rescue of F508del CFTR processing (this paper, [39]) and further reduction of NFκB activity [40]. The gene discussed is NFKB1; the disease is cystic fibrosis.