TNF and obesity due to melanocortin 4 receptor deficiency: A disruption of the 5-LOX pathway in hyperlipidemic apolipoprotein E (apoE) deficient mice reduces hepatic inflammation and tumor necrosis factor alpha (TNFα) dependent hepatic injury, and deficiency in leukotriene B4 receptor 1 (LTB4R, also known as BLT1), alleviates systemic insulin resistance in diet-induced obesity [175,176].