LCN2 and obesity due to melanocortin 4 receptor deficiency: While LCN2 deficiency has been shown to improve insulin resistance and diabetic encephalopathy [20, 53], others have found that LCN2 (-/-) mice were more susceptible to HFD-induced obesity and LPS-induced sepsis [19, 22], and one study has suggested that LCN2 deficiency plays only a minor role in mice fed with HFD [54].