PLCG2 and Alzheimer disease: PLCG2 is an AD-linked gene encoding the intracellular enzyme PLCγ2 which cleaves the membrane phospholipid phosphatidylinositol-4,5-bisphosphate (PIP2) to inositol-1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) [53, 54].