SERPINE1 and Nasal polyposis: We detected increased activity of coagulation factor XIII-A (F13A1), decreased expression of fibrinolytic genes (plasminogen, PLG and tissue type plasminogen activator, PLAT), and increased expression of inhibitors of fibrinolysis (serpin family E member 1, SERPINE1 and serpin family B member 2, SERPINB2) in the Responder group, which could explain the fibrin accumulation in nasal polyps (Figure 2B).