Summary of metabolic precursors and biosynthetic enzymes of putative ligands for PPARα and PPARγ. Both receptors bind DNA as heterodimers with RXRα to specific PPAR-response elements (PPREs) in target genes, although the binding is cell type-specific. oxLDL, oxidized LDL; LPL, lipoprotein lipase; 8(S)-HETE, (8S)-hydroxyeicosatetraenoic acid; LNO2, nitrolinoleic acid; 15-dPGJ2, 15-deoxy-Δ12,14-prostaglandin J2.