These studies have implicated CF-associated alterations in transforming growth factor β (TGF-β), bone morphogenetic protein (BMP), phosphatase and tensin homolog (PTEN), AKT, wingeless-related integration site (WNT/β-catenin), and pancreatic duaodenal homeobox-1 (PDX1) signaling pathways and changes in the expression of proteins that directly bind with CFTR.16 This evidence concerns the gene PTEN and cystic fibrosis.