INS and Prader-Willi syndrome: PC1 is a protein involved in several hormonal pathways and this may explain the hormonal changes found in PWS: Growth hormone-releasing hormone (GHRH) (growth hormone deficiency and short stature); proGnRH (hypogonadism); progrelin (hypergrelinemia); proinsulin (relative hypoinsulinemia and type 2 diabetes mellitus); proopiomelanocortin—POMC (hypocortisolism); and ProTRH (hypothyroidism) [36].