CFTR and cystic fibrosis: GJA1 (Connexin 43), also up-regulated in CF, suppresses cell proliferation via maintenance of cell-cell communication, possibly via an association with CAV1 [45], which has an important role in maintenance of airway ECM integrity via inhibition of the TGF beta-induced fibrosis [46], and may also play an important role in modulating the immune response to P. aeruginosa infection through the formation of CFTR-expressing lipid rafts [47].