LEP and obesity due to melanocortin 4 receptor deficiency: Leptin regulates energy homeostasis through the leptin receptor (LEPR), and the overexpression of LEP and LEPR links obesity with breast cancer.133 A study conducted with 320 female subjects from Jordan investigated the impact of the SNP rs1137101 within the LEPR.59 rs1137101 is associated with an A to G substitution in LEPR, which alters leptin binding, thus leading to increased serum leptin.