Using qRT-PCR, we confirmed that the expression of PSMD1 (p = 0.017), PSMA2 (p = 0.018), PSMB3 (p = 0.0003) and PSMB6 (p = 0.0003) was markedly increased in muscle of patients with T2D compared with obese individuals (Figure 2a–d). Here, PSMD1 is linked to type 2 diabetes mellitus.