PTGS2 and chronic obstructive pulmonary disease: Other mediators include IL-8, which is involved in inflammatory cell recruitment in COPD [18]–[21], especially with bacterial infection at exacerbation [20], [21]; and cyclooxygenase-2 (COX-2), an inducible enzyme that catalyzes arachidonic acid transformation into thromboxane and prostaglandins [12].