The resistance of pigs to diet- and obesity-induced hypertriglyceridemia is not well understood but could be related to the lack of functionally effective cholesteryl ester transfer protein (CETP) [48], extrahepatic lipogenesis [49], or any of the other ways; lipoproteins and their metabolism differ in pigs and man [48, 50]. Here, CETP is linked to obesity due to melanocortin 4 receptor deficiency.