The LTB4-LTB4R (BLT1) pathway, because of its significant immunological role, has been implicated in the pathophysiology of a number of diseases, including asthma (including airway hyper-responsiveness, severe attacks and asthma exacerbations) [97], atherosclerosis, Alzheimer’s disease [120], obesity-related inflammation [121], and inflammatory bowel disease [101]. Here, LTB4R is linked to obesity due to melanocortin 4 receptor deficiency.