15(R)-HETE, a monohydroxy fatty acid, is synthesized from arachidonic acid via aspirin-acetylated COX-2, leading to the formation of specialized pro-resolving mediators 15(R)-lipoxin A4 and B4 through a transcellular mechanism involving 5-lipoxygenase (5-LO). Additionally, this compound is produced by the cytochrome P450 (CYP) isoform CYP2C9 and can be generated from arachidonic acid by COX-1 in human mast cells, where it accumulates due to its resistance to conversion into 15-KETE by 15-hydroxyprostaglandin dehydrogenase (15-PGDH). As an agonist of PPARβ δ, 15(R)-HETE induces the expression of a target gene in NIH3T3 cells, demonstrating its biological significance.