RAP1A and Alzheimer disease: By using Western blotting to verify the above‐mentioned nine target proteins (PHB, RAP1A, ITPR1, UQCRH, CD63, ADAM10, GP1BA, ITPR2, and FINC), we observed a decreasing trend of the levels of PHB, CD63, GP1BA, and FINC in MCI or/and AD, which was consistent with the proteomic results, but no significant decrease for the other five molecules (Figure S1).