Data derived from transcriptome and secretome analyses of primary ascite‐derived cells indicate that (a) the major route of LPA synthesis is the consecutive action of a secretory phospholipase A2 (PLA2) and autotaxin, (b) that the components of this pathway are coordinately upregulated in ascites, and (c) that CD163+CD206+ tumor‐associated macrophages play an essential role as main producers of PLA2G7 and autotaxin. This evidence concerns the gene MRC1 and neoplasm.