APOB and obesity due to melanocortin 4 receptor deficiency: In particular, 2 peptides belonged to apolipoprotein C III (Apo CIII, m/z 1716, and 1773 dysregulated in obesity after Hu14 depletion), five peptides to alpha-1-antichymotrypsin (AACT, m/z 1736, 1818, 2111, and 2135 dysregulated in obesity after Hu14 depletion and 3777 after Hu7), and three to apolipoprotein B100 (Apo B100, m/z 1582, 1796 and 2046 dysregulated in obesity after Hu14 depletion).