PIK3C3 and cystic fibrosis: First, the functional sequestration of phosphatidylinositol 3-kinase catalytic subunit type 3 (PIK3C3) and of UV radiation resistance-associated-gene (UVRAG), two major components of the BECN1 complex, negatively impacts on intracellular trafficking in CF epithelial cells, as it reduces the availability of phosphatidyl-inositol-3-phosphate (PtdIns3P) at early endosomes and perturbs endosomal fusion/maturation and trafficking [6, 12, 13].