FADS6 and obesity due to melanocortin 4 receptor deficiency: It is, however, beyond the scope of the present study to discuss the potential markers associated with obesity, such as the genes associated with fatty acids (SLC27a4, FADS2, FA2H, and FADS6; all up-regulated by FD) and insulin treatment (INSIG1 up-regulated and IRS1, IGFBP2; all down-regulated by FD) (Table S2).