Western blot analysis of endogenous cystic fibrosis transmembrane conductance regulator (CFTR) and apical recycling, exocytic, and ion transport proteins in polarized Caco-2BBe cells. Caco-2BBe cell lysates (20 μg) were resolved by SDS-PAGE, and proteins were detected by Western blot. Bands show endogenous expression of endocytic (EEA-1, myosin VI) and apical recycling (rme-1, rab11) proteins and exocytic proteins involved in vesicle fusion (SNAP 23, munc-18, syntaxin 3), basolateral chloride entry transport (NKCC1), and apical exit (CFTR). Control immunoblots probed with relevant IgG and β-actin loading are shown. Molecular mass standards (kDa) are indicated.