However, further investigation of the efficacy of rosiglitazone in Alzheimer’s disease, either as a monotherapy or an adjunctive therapy to acetylcholine esterase inhibitors, in five Phase III clinical trials, did not yield meaningful outcomes in cognition and global function, even when the patients were stratified into APOE ε4 carriers or non-carriers [229,230]. This evidence concerns the gene APOE and Alzheimer disease.