 DNA-rich extracellular fibril matrixes able to kill extracellular pathogens while minimizing tissue; hence these hepoxilins may contribute to innate immunity by being responsible of the direct killing of pathogens.In addition to 12"S"-HETE and 12"R"-HETE (see 12-HETE#Blood pressure), HxA3, TrXA3, and TrXC3 but neither HxB3 nor TrXB3 relax mouse mesentery arteries pre-contracted by thromboxane A2)(TXA2).Mechanistically, these metabolites form in the vascular endothelium, move to the underlining smooth muscle, and reverse the smooth muscle contraction caused by TXA2 by functioning as a Receptor antagonist, i.e.