GLP1R and obesity due to melanocortin 4 receptor deficiency: Regarding GLP1R rs6923761, it has been shown to relate with metabolic and obesity parameters, such as body mass index, weight, fat mass, waist circumference, triglycerides, insulin, HOMA-IR, and HDL cholesterol (de Luis et al., 2013, 2014a,b,c,e, 2015b,d, 2018), weight loss (de Luis et al., 2014a,d), cardiovascular risk in patients with obesity (de Luis et al., 2018), type 2 diabetes (de Luis et al., 2015a).