Because the two subtypes of AD have different levels of immune infiltration and hypoxia, in order to guide clinical medication more accurately, we also screened nine genes, namely, ATP7B, LIAS, DLD, GLS, MTF1, LIPT1, PDHA1, SLC31A1, and PDHB, in order to distinguish the two subtypes of AD, and constructed a diagnostic model based on these genes. The gene discussed is DLD; the disease is Alzheimer disease.