text: LPA is the result of phospholipase A2 action on phosphatidic acid.  The SN-1 position can contain either an ester bond or an ether bond, with ether LPA being found at elevated levels in certain cancers.  LPA binds the high-affinity G-protein coupled receptors LPA1, LPA2, and LPA3 (also known as EDG2, EDG4, and EDG7, respectively).