EGF and chronic rhinosinusitis with nasal polyps: Furthermore, this EGF-induced upregulation of MUC5AC can be blocked by pretreatment of specific inhibitors of TMEM16A and PI3K (Fig. 6), suggesting that EGF-PI3K-TMEM16A signalling is likely to play an important role in MUC5AC expression in CRSwNP patients.