Eight key genes (ACTN4, BGN, PRELP, TSFM, UBC, ELAVL1, NRF1, and SUMO2) related to the comorbidities AD, T2DM, and HTN were identified by integrating the shared genes at the levels of DEGs, common modules, and FC-based driver genes. The gene discussed is SUMO2; the disease is Alzheimer disease.