PTGS2 and Cognitive impairment: While independent epidemiological studies indicate that non steroidal anti-inflammatory drugs (NSAIDs) administration prevents or delays the onset and risk of developing Alzheimer's disease [61-63], clinical trials using COX-2 selective inhibitors in patients with mild to severe cognitive impairment, have been unsuccessful to date [64-67], with the exception of a small double blind, placebo-controlled study with indomethacin, a preferential COX-1 inhibitor [68].