MUC5AC and allergic rhinitis: Although no significant differences in EPX-IgG levels were observed in the supernatants of nasal secretion obtained from healthy volunteers, patients with ECRS, patients with CRS (non-ECRS), and patients with allergic rhinitis, the EPX-IgG levels in the supernatants of mucin obtained from patients with refractory ECRS were markedly elevated compared with those in the supernatants of nasal secretion from other subjects (Figure 3B).