Phospholipase A1 member A (PLA1A, aka PS-PLA1) is a widely expressed, extracellular protein belonging to the pancreatic lipase family. Phospholipases are conserved in a wide range of organisms. PLA1A specifically hydrolyses PS to produce its corresponding lysophospholipid 2-acyl LPS. Lysophospholipids in general can act as lipid mediators with multiple biological functions so PLA1A could play an important role in mediating 2-acyl LPS production (Nagai et al. 1999, Aoki et al. 2007).