We were the first to observe that the inducible isoform, PLD1, but not the constitutive isoform, PLD2, shows elevated synaptosomal expression (thus complementing the earlier studies that established that PLD1 was also aberrantly elevated in astrocytes and mitochondrial fractions) in the post-mortem hippocampi of AD brains compared to age-matched controls. This evidence concerns the gene PLD1 and Alzheimer disease.