At both cg00574958 and cg17058475–CPT1A, cg12729894–CTSD, cg22948094–CTNNB1, and cg15150970–DNMT3A, we detected suggestive or significant associations of DNA methylation levels with AD risk, clinical diagnosis of cognitive status, or AD-related indices in FHS or ROSMAP participants. The gene discussed is CTSD; the disease is Alzheimer disease.