SMAD4 and pancreatic neoplasm: Studies were selected using the following search terms (non-exhaustive list): “pancreas”, “pancreatic cancer”, “ pancreatic ductal adenocarcinoma”, “PDAC”, “TGF-beta”, “SMAD4”, “epithelial-mesenchymal transition”, “EMT”, “hybrid EMT”, “partial EMT” and/or “epithelial-mesenchymal plasticity”.