Several reports have suggested the role of other chemotactic factors in obesity-induced macrophage infiltration and IR, including CXCL-10 or interferon-γ-inducible protein 10 (IP-10), which is a potent chemoattractant for various leukocyte subsets. The gene discussed is CXCL10; the disease is obesity due to melanocortin 4 receptor deficiency.