LEPR and obesity due to melanocortin 4 receptor deficiency: A previous study reported that an increased copy number in the "E2 DNA" region (exon-intron junction) of the LEPR gene lead to an increased fat deposition in humans, and LEPR CNV is thought to be involved in obesity and type 2 diabetes mellitus [61]; this suggests that artificial selection in cattle seems to have selected for a trait that in other biological systems occurs as a rare disease.