Across all 4 algorithms used and the comprehensive ranking analysis by the RefFinder tool, ACTB and/or YWHAZ were predicted to be the most stable genes, while PPIB was consistently the least stable gene in all samples and separately in the NGT group and GAPDH was the least stable gene in the T2DM group (Fig. 1). Here, GAPDH is linked to type 2 diabetes mellitus.