GLP1R and obesity due to melanocortin 4 receptor deficiency: In 2022, the authors of [25] discovered remarkable antidiabetic in vivo activity of (4-{[1-({3-[4-(trifluoromethyl)phenyl]-1,2,4-oxadiazol-5-yl}methyl)piperidin-3-yl]methyl}morpholine (Figure 13), which acts as positive allosteric modulator (PAM) of GLP-1R (glucagon-like peptide-1 receptor), which helps to reduce food intake in obesity and to improve glucose handling in normal and diabetic patients.