SMAD4 and pancreatic neoplasm: The tumor suppressor mothers against decapentaplegic homolog 4 (SMAD4) (also known as deleted in pancreatic cancer 4 (DPC4)) was first described in 1996 by Hahn and co-workers and is thought to regulate pancreatic cell proliferation and apoptosis via the transforming growth factor-β (TGF-β) pathway [5,6].