Fourthly, hypotheses such as autophagy54 and gut dysbiosis55 represented distinct signaling pathways in AD, and more genes were implicated in Aβ clearance, including APOE,56 clusterin,57 α2‐Macroglobulin,58 and triggering receptor expressed on myeloid cells 2.59 The gene discussed is APOE; the disease is Alzheimer disease.