The novelty of the approach we used is that it provided a set of peptides from Apo CIII, Apo A1, Apo B100, LPL, AACT, CC3 to be targeted in patients adopting MS methods based on absolute quantification through a single-reaction-monitoring (SRM) approach35,36, possibly allowing to identify disease specific patterns that can be translated to clinical laboratory for risk assessment in obesity and personalized medicine. This evidence concerns the gene SERPINA3 and obesity due to melanocortin 4 receptor deficiency.