These results were confirmed and extended using Npc1 heterozygous (Npc1+/-) mice, which compared to Npc1 normal (Npc1+/+) and Npc1 homozyous (Npc1-/-) mice, had livers with an increased expression of caveolin-1 and concentration of triacylglycerol, which is a prominent metabolic feature of obesity [65-67]. This evidence concerns the gene NPC1 and obesity due to melanocortin 4 receptor deficiency.