The 12-lipoxygenase metabolite of arachidonic acid, 12(S)-HETE, was shown to function as an agonist of the orphan GPCR GPR31 and to increase the invasiveness of PC3M adenocarcinoma cells in a GPR31-dependent manner [26]; other studies described 12(S)-HETE as a vasorelaxant, which appears to act as an antagonist of the thromboxane-A2 receptor [27]. Here, GPR31 is linked to adenocarcinoma.