The PPI network identified hub proteins, of which the hub proteins, including TXN, PSMD7, FCER1G, ATP6V0C, COX4I1, COX5B, YWHAQ, PPP2CA, and PPP1CA, were dominant in the T2DM group, highlighting the importance function of these hub proteins in the biological regulation of the T2DM development (Fig. 2E), while AKT1 and WAS were dominant in the HC group (Fig. 2F). Here, COX5B is linked to type 2 diabetes mellitus.