CX3CL1 and obesity due to melanocortin 4 receptor deficiency: These data show that CX3CL1-s expression in the hypothalamus is sufficient to recapitulate the anti-obesity effects of full length CX3CL1 [20] but ensures a microglial site of action since CX3CR1 is expressed exclusively by microglia in the CNS (Supplementary Figure S1).