Further, other essential molecular players, like amyloid-β protein precursor (AβPP), β-site APP cleaving enzyme 1 (BACE1), C-terminal fragment (CTF) of 99 amino acids (C99), the γ-secretase complex, and APP intracellular domain (AICD), closely associated with the pathogenesis of AD, are all detected at MAM junctions [45, 83]. The gene discussed is BACE1; the disease is Alzheimer disease.