Among the five developed global AR-KO mice, including deletion of its DNA-binding domain, only two lineages (constructed by Kato’s group and by Chang’s group) significantly exhibit late-onset obesity accompanying the accumulation of visceral fat34, 35, 36, 37, 38, whereas the other three lineages did not exhibit the phenotype. This evidence concerns the gene AR and obesity due to melanocortin 4 receptor deficiency.