We investigated the physiological and biochemical characteristics of obesity-resistant mice (ORM) and functional parameters of their bone marrow granulocytes, namely NADPH-oxidase-mediated ROS generation in resting cells and cells stimulated by agonists of membrane formyl peptide receptors (Fpr1, Fpr2). Here, FPR2 is linked to obesity due to melanocortin 4 receptor deficiency.