Obesity and hyperlipidemia are known to significantly impact aspects of cholesterol metabolism and HDL biology and may impact aspects of CETP-mediated biology (Cappel et al., 2013; Palmisano et al., 2016; Zhu et al., 2018a; van den Boogert et al., 2020). This evidence concerns the gene CETP and obesity due to melanocortin 4 receptor deficiency.