SLC2A4 and obesity due to melanocortin 4 receptor deficiency: Relative to fatty acid metabolism, we observed DM-specific decrease in VAT gene expression and protein abundance of FASN, a central lipogenic enzyme, accompanied by decreased gene expression of key regulators of adipogenesis and lipogenesis such as PPARG, CEBPA, ADIPOQ, and GLUT4. Multiple studies of transcriptomics and functional analyses of adipose tissue demonstrate defects in fatty acid synthesis in general and FASN specifically in obesity and DM4,10–12.