In vivo mouse and in vitro human islet studies suggested that beta cells are dedifferentiated in type 2 diabetes, as they lose expression of the typical beta cell transcription factors, including MafA (MAF bZIP transcription factor A), NKX6.1 (NK6 homeobox 1) and PDX1 (pancreatic and duodenal homeobox 1) [6–8]. Here, PDX1 is linked to type 2 diabetes mellitus.