LGALS1 and obesity due to melanocortin 4 receptor deficiency: To confirm the role of galectin-1 in an in vivo mouse model of obesity, male wild-type (Lgals1+/+) and galectin-1 knockout (Lgals1−/−) mice (n = 5 per group) were fed a high-fat diet (HFD) containing 60% fat for 10 weeks (Fig. 4a).