DAG1 and astrocytic tumor: In human astroglioma cells, epigallocatechin gallate regulates phosphatidylcholine-specific phospholipase D (PLD) activity via a signaling pathway involving changes in the redox state that stimulates a PLCγ1/IP3/CaMK II/PLD and a PLCγ1/DAG/PKC/PLD axes [28].