UQCRC2 and type 2 diabetes mellitus: The proteins displayed by cluster 2 were stable in T2DM vs. Ctrl but were significantly up-regulated in T2DM-MCI vs. T2DM-nMCI (Figure 1C), including alpha-1-antitrypsin (SERPINA1), PP2A cancer inhibitor (CIP2A), major prion protein (PRNP), mitochondria-related proteins cytochrome b-c1 complex subunit 2 (UQCRC2), valosin-containing protein (VCP), and stress-70 protein (HSPA9), involving cellular response to the heat stress biological process (Figure 1D).