We chose to validate the 6 proteins: Dipeptidyl peptidase-4 (DPP4), prolactin-induced protein (PIP), neutrophil gelatinase-associated lipocalin (NGAL), L1 cell adhesion molecule (L1CAM), thrombospondin-2 (THBS2), and glucagon-like peptide 1 (GLP1), related to metabolism or inflammation, which could be validated by enzyme-linked immunoassay and were higher expression in T2DM patients, for differentiation between with and without complications in another cohort of population. The gene discussed is DPP4; the disease is type 2 diabetes mellitus.