APOE and obesity due to melanocortin 4 receptor deficiency: It has been reported that CXCR3 mediates T-lymphocyte migration to the adipose tissue under chronic inflammatory conditions, in particular, induced by obesity.[30, 31] In addition, a high-fat diet in rodents was shown to induce CXCR3 expression in the adipose tissue as a result of increased inflammation.[32] In the current study, the diet schedule may have induced chronic inflammation in the adipose tissue of both the ApoE KO mice and C57BL/6 control mice, resulting in high uptake of [18F]1 in the BAT region.