PLA2G6 and Alzheimer disease: Given that iPLA2 has been proposed to be highly specific to DHA cleavage/release [37, 69], to be enriched in AD-vulnerable brain regions (cortex and hippocampus) [87, 132], and to account for more than 70% of the brain PLA2 activity [132], we reasoned that the increases of free DHA found in our lipidomics analysis were likely due to the increased activity of iPLA2 in APP-Tg mice.