ESR1 and obesity due to melanocortin 4 receptor deficiency: The authors (14) firstly confirmed that treatment of HFD after weaning induced obesity and precocious puberty in female rats and upregulated HPGA gene expressions, including Kiss1 (kisspeptin-1), GPR54 (G protein-coupled receptor 54, Kiss1R), GnRH (gonadotropin-releasing hormone), Erα (estrogen receptor α) in the hypothalamus, GnRHR (gonadotropin-releasing hormone receptor) in the pituitary, and LHR (luteinizing receptor), FSHR (follicle-stimulating hormone receptor), and Erα in the ovary.