13(S)-HPODE is a linoleic acid metabolite found in several plants and mammals. In Vitro: 13(S)-HPODE can be produced by the oxidation of linoleic acid by lipoxygenase-1 in many plants^[1]. The dioxygenation catalyzed by a 15-lipoxygenase and a reduction of intermediate 13-HPODE by a glutathione-dependent peroxidase can form 13(S)-HODE^[2]. 13(S)-HPODE can stimulate EGF-dependent mitogenesis and up-regulation of EGF-dependent tyrosine phosphorylation by inhibiting the dephosphorylation of the EGFR^[3].