In humans, heterozygous PDX1 mutations are known to cause PDX1-MODY, a type of monogenic diabetes known as Maturity Onset Diabetes of the Young (MODY) (3), with symptoms of variable severity including hyperglycemia, pancreatic hypoplasia, general impaired beta cell function, polyhormonal endocrine cells and an increased susceptibility to Type 2 Diabetes (4). Here, PDX1 is linked to type 2 diabetes mellitus.