For instance, hPL in normal pregnancies enhances pancreatic insulin production when it binds its receptor in pancreatic beta cells through pancreatic and duodenal homeobox 1(PDX1) expression [54], although it has also been reported to act as an insulin antagonist [55,56], and mouse models lack the early expression of receptors for hPL generate obesity, hyperleptinemia and glucose intolerance [57]. This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.