HIPK2 and diabetes mellitus: Among the different HIPK2 inhibitors available, we choose the 5-ITu because it strongly inhibits HIPK2 kinase activity in vitro [36] and, most relevant for this study, it supports the replacement capacity of endocrine pancreatic beta-cells in rodents for diabetes treatment [23], indicating that 5-ITu is not detrimental, at least, for the endocrine pancreas.