Thus, to achieve internalization of the ectopically expressed surface β1-integrins on CF airways, we subjected Cftr−/− mice (Figures 3A–3C) or CFMHH mice (Figure 3B) either to inhalation of nebulized anti-β1-integrin antibody clone 9EG7, which binds the partly or fully active conformation of β1-integrin molecules (Lenter et al., 1993), or to inhalation of RGD peptides, which bind to the fibronectin binding site of the receptor (D’Souza et al., 1988). Here, FN1 is linked to cystic fibrosis.