Animal studies have found that amidation-modified Apelin-13 might significantly reduce the average diameter of adipocytes, mRNA and protein expression of peroxisome proliferator-activated receptor γ (PPARγ) levels and perilipin 1 (PLIN1), thereby improving the dyslipidemia caused by obesity (14). Here, PPARG is linked to obesity due to melanocortin 4 receptor deficiency.