To evaluate the role of Msr1 on obesity-associated impaired glucose metabolism and insulin resistance, 8-week-old male Msr1KO and Msr1HET mice were fed HFD to induce obesity, then assessed by glucose (GTT) and insulin tolerance tests (ITT) at 14 and 15 weeks HFD, respectively. The gene discussed is MSR1; the disease is obesity due to melanocortin 4 receptor deficiency.