ABCG2 and obesity due to melanocortin 4 receptor deficiency: Moreover, metabolites associated with the cAMP signalling pathway, ABC transporters, neuroactive ligand−receptor interaction and regulation of lipolysis in adipocytes were dramatically changed in the HSPEN group compared with the ND group (Figure 5D); these pathways are involved in cystic fibrosis, obesity and NAFLD (Reynisdottir et al., 1995; Manson et al., 2011; Fuchs et al., 2014).