CX3CL1 and obesity due to melanocortin 4 receptor deficiency: Accordingly, certain chemokines, such as the C-X3-C motif chemokine ligand 1 (CX3CL1, or ‘fractalkine’), promote obesity when chronically administered in the brain [82], whereas inhibition of CX3CL1 actions in the hypothalamus of DIO mice through an approach of small interfering RNA reduced local inflammation and led to weight loss and to improvements in systemic glucose metabolism [82].