EGR1 and obesity due to melanocortin 4 receptor deficiency: For example, whole body Egr1-deficient mice fed a high fat diet are less susceptible to diet-induced obesity and obesity-associated disorders such as insulin resistance, hyperinsulinemia, hyperlipidemia, and fatty liver, which largely depends on the increase of energy expenditure in the adipose tissue of Egr1-null mice[20].