Increased macrophages and T-cells have been previously reported in skeletal muscle with obesity, while mast cells, eosinophils, neutrophils, B cells, NK cells were not changed with obesity.46 We extend our previous findings to show that 5FU reduced monocytes and macrophages, particularly reducing inflammatory CD11b+Ly6cHi and CD68+CD11c+CD206− cells after three cycles. This evidence concerns the gene MRC1 and obesity due to melanocortin 4 receptor deficiency.