Figure 1. Pancreatic transcription factor hierarchy during pancreas development.

It is well known that many transcription factors are involved in pancreas formation and β-cell differentiation. Among the various transcription factors, PDX-1 plays a crucial role in pancreas formation and β-cell differentiation as well as maintenance of mature β-cell function. Ngn3 and NeuroD are also important transcription factors for pancreatic endocrine cell differentiation. MafA expression is induced at the final stages of β-cell differentiation and functions as a potent activator of insulin gene transcription.