These observations prompted us to speculate whether E11 deficiency leads to altered expression of leptin, a pleiotropic adipocytokine that is known to be associated with obesity, adipose tissue inflammation, and cancer (Myers et al., 2010; Abella et al., 2017; de Candia et al., 2021). The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.