One group of 30 patients with MCI and AD demonstrated improved memory and stabilized plasma Aβ42 concentration after six months of treatment with rosiglitazone [175]; in addition, a phase 2 trial revealed cognitive improvement after 24 weeks of treatment with rosiglitazone in only APOE ε4 non-carriers [176], whereas a phase 3 trial showed no effects on cognition, regardless of APOE genotype [177]. The gene discussed is APOE; the disease is Alzheimer disease.