1-Palmitoyl-2-hydroxy-sn-glycero-3-PC is the ubiquitous lipid species generated following phospholipase A2 (PLA2) hydrolysis of phosphatidylcholine. The hydrolysis of phospholipids by arachidonoyl-selective PLA2s is the initiating event in many eicosanoid-based signal transduction pathways. Many other reactions also generate phosphatidylcholine species with a free hydroxyl group in the sn-2 position. 1-Palmitoyl-2-hydroxy-sn-glycero-3-PC augments inflammation through effects on adhesion molecules and growth factors, monocytes, and macrophages. The lymphocyte G protein-coupled receptor G2A binds 1-palmitoyl-2-hydroxy-sn-glycero-3-PC as a specific ligand with a Kd of 65 nM; this receptor also binds the related phospholipid sphingosyl phosphorylcholine.