We identified 15 crucial DEAGs closely associated with AD by a series of bioinformatics analysis, including IGF1R, MXI1, RB1, PPARA, NFE2L2, STAT5B, FOS, PRKCD, YWHAZ, HTT, MAPK9, HSPA9, SDHC, PRKDC, and PDPK1. The gene discussed is MAPK9; the disease is Alzheimer disease.