FTO and obesity due to melanocortin 4 receptor deficiency: Next, we investigated the gene expression pathways affected by the FTO rs1421085 SNP and found that genes, which were less expressed in active beige adipocytes that carried the obesity-risk genotype, were overrepresented in several pathways, such as metabolic, PPAR signaling, lipolysis, fatty acid metabolism, or TCA cycle (Figures 2E, F).