Specifically, the proteins associated with the central system, including the well-known PRNP, CIP2A, fructose-bisphosphate aldolase B (ADLOB), and fructose-1,6-bisphosphatase 1 (FBP1) and the less-known SERPINA1 and VCP, were increased in T2DM-MCI compared with T2DM-nMCI, in which ADLOB and FBP1 were involved in metabolic acidosis (Figure 2B). Here, PRNP is linked to type 2 diabetes mellitus.