In addition, obesity-related metabolic disease has been viewed as unresolved inflammatory disease; thus, regulation of immunity is a promising approach for treating chronic metabolic disorders.35, 42 In the present study, using a combination of an in vivo genetic deletion model and an in vitro reconstruction system, pivotal roles were identified for Alox15 expression in macrophages for non-inflammatory efferocytosis of dying adipocytes and β3-adrenergic remodeling of adipose tissue. This evidence concerns the gene ALOX15 and obesity due to melanocortin 4 receptor deficiency.