Transcriptional activator. Binds to the E-box consensus sequence 5'-CANNTG-3'. Plays an important role in determining whether cells allocated to the pancreatic buds continue towards pancreatic organogenesis or revert back to duodenal fates. May be involved in the maintenance of exocrine pancreas-specific gene expression including ELA1 and amylase. Required for the formation of pancreatic acinar and ductal cells. Plays an important role in cerebellar development. Defects in PTF1A are the cause of diabetes mellitus and cerebellar hypoplasia/agenesis (DMCH). Note: This description may include information from UniProtKB.