ACHE and diabetes mellitus: Moreover, the drug repurposing analyses using the biomarker signatures from our studies (Table 4) yielded drug candidates such as pioglitazone (a diabetes medication, previously studied for AD prevention in clinical trials that may have been too heterogeneous in enrollment), levonorgestrel (a progesterone derivative), and the natural compounds salsolidine (a natural compound with acetylcholinesterase inhibitory properties), ginkgolide A (a natural compound with neuroprotective effects) and icariin (a natural compound reported to improve memory impairment in Alzheimer’s disease model mice).