In the exercise scenario, despite the presence of obesity, in both mice and humans, increased IL-6 levels potentially enhance insulin and glucagon-like peptide-1 (GLP-1) secretion, improving glucose tolerance and insulin sensitivity (Ellingsgaard et al., 2011; Benrick et al., 2012; Lang Lehrskov et al., 2018; Wedell-Neergaard et al., 2019; Ellingsgaard et al., 2020). The gene discussed is GCG; the disease is obesity due to melanocortin 4 receptor deficiency.