LCN2 and obesity due to melanocortin 4 receptor deficiency: Law et al. demonstrated that insulin resistance and obesity could be improved in mice with LCN2 gene KO, suggesting LCN2 to be a risk factor, wherein the study by Guo et al. showed that insulin resistance and obesity could be potentiated in mice with LCN2 gene KO, suggesting LCN2 to be a protective factor [16, 39].