In the second stage, acute and chronic ischemic dysfunction of the BBB with leakage of the β-amyloid peptide from the plasma into the brain parenchyma triggers additional death of ischemic neurons dependent on amyloid and finally develops amyloid plaques and ends in full-blown dementia with the AD phenotype [12,18,20,26,39,41,74,104,130]. The gene discussed is PPIB; the disease is dementia.