For example, the glucagon-like peptide-1 receptor with 30 DNA variants in BN.SHR20 has been a heavily exploited target of type 2 diabetes and obesity therapies by its agonists [48], and the peroxisome proliferator-activated receptor beta/delta is crucial for fatty acid metabolism in the muscle [49]. Here, PPARD is linked to obesity due to melanocortin 4 receptor deficiency.