GCG and obesity due to melanocortin 4 receptor deficiency: People with obesity and/or T2D have impaired incretin release (Toft-Nielsen et al., 2001; Vilsbøll et al., 2001) and/or function (Nauck et al., 1986; Muscelli et al., 2008), and GLP-1-targeted therapies offer effective management of body weight and blood glucose levels, with underlying improvements to β-cell function and peripheral insulin sensitivity (Zander et al., 2002; Hinnen, 2017).