This gene encodes a member of the epidermal growth factor (EGF) family. These growth factors are ligands for the EGFR/ErbB receptor tyrosine kinases, and play roles in cell growth and differentiation. The encoded protein is synthesized as a transmembrane precursor that is proteolytically cleaved to generate a mature peptide, and plays a role in the differentiation of pancreatic beta cells. This gene may also play a protective role in acute pancreatitis, whereas increased expression of this gene may contribute to diabetic macular edema. Gene therapy using combinations of this gene and other pancreas-specific transcription factors may induce islet neogenesis and remediate hyperglycemia in type 1 diabetes. [provided by RefSeq, Apr 2011]