For example, NKX6.1 is essential for both early and late stages of pancreatic development with a critical role in the formation of β cells [50–52], KLF14 is an important regulator of metabolic diseases, such as diabetes and obesity[53, 54], and E2F3 activates β-cell proliferation [55]. This evidence concerns the gene KLF14 and obesity due to melanocortin 4 receptor deficiency.