S. aureus acts through two signaling pathways to activate inflammasomes to promote AD: (1) Signal 1: S. aureus acts on TLRs and TNFR1, interacts with NOD2, activates NF-kB, induces gene transcription, produces Pro-IL-1β, and synthesizes raw materials for the inflammasomes. The gene discussed is NOD2; the disease is Alzheimer disease.