Interestingly, the sex-specific microglial responses to high-fat diet feeding in mice are also mediated by Cx3cr1 signaling, whereas Cx3cr1 knockout female mice developed ‘male-like’ hypothalamic microglial accumulation and activation with increased susceptibility to diet-induced obesity 39. The gene discussed is CX3CR1; the disease is obesity due to melanocortin 4 receptor deficiency.