In this backdrop, the aim of this study was to evaluate stability of expression of 4 widely used reference genes: Beta-actin (ACTB), Peptidylprolyl Isomerase B (PPIB), Tyrosine 3-Monooxygenase/Tryptophan 5-Monooxygenase Activation Protein Zeta (YWHAZ), and GAPDH in PBMCs from T2DM patients and healthy control subjects. This evidence concerns the gene PPIB and type 2 diabetes mellitus.