FTO and obesity due to melanocortin 4 receptor deficiency: To date, over 300 genes have been identified as closely related to obesity, such as leptin receptor (LEPR) gene, pro-opiomelanocortin (POMC) gene, LEP gene, FTO gene, neuropeptide Y (NPY) gene, and melano-cortin-4-receptor (MC4R) gene, etc. These human obesity-related genes are predominantly located on the chromosomes 2, 7, 16, 17, and 18 and play a significant role in regulating energy intake and consumption within the body [104].