Lecithin cholesterol acyltransferase (LCAT) is a key enzyme in the esterification of plasma cholesterol. Group XV phospholipase A2 (PLA2G15 aka LCAT-like lysophospholipase, LLPL or lysosomal phospholipase A2, LPLA2) bears 49% sequence similarity to LCAT (Taniyama et al. 1999) and is present in plasma. PLA2G15 possesses both calcium-independent phospholipase A(2) and transacylase activities (Abe & Shayman 1998) and could hydrolyse lysophosphatidylcholine (lysoPC), a proatherogenic lipid, to glycerophosphorylcholine (GPCho) and a free fatty acid anion (LCFA(-)) (Taniyama et al. 1999, Hiraoka et al. 2002).