In a diet-induced obesity model, pitaya-peel-derived betacyanins were found to induce fatty acid oxidation, decrease fatty acid biosynthesis by increasing adiponectin receptor 2 (AdipoR2) and carnitine palmitoyltransferase I (Cpt1) expression and decreasing fatty acid synthase (Fas) gene expression, and ameliorate hepatosteatosis [16]. The gene discussed is FASN; the disease is obesity due to melanocortin 4 receptor deficiency.