The most intriguing example is LCN2, as the metabolic phenotype of the respective knockout mice was distinct in three independent laboratories: Law et al (2010) reported that LCN2 deficiency protects mice from obesity-induced insulin resistance, whereas Guo et al (2010) showed LCN2-dependent promotion of metabolic dysfunction (Guo et al, 2010; Law et al, 2010). The gene discussed is LCN2; the disease is obesity due to melanocortin 4 receptor deficiency.