MUC5AC and asthma: ILIRL1 is associated with Th2 inflammation [37] as well as goblet cell hyperplasia [38], which is in concord with the increased mucus production in the peripheral airways in severe asthma in our study, reflected by markers of mucus production, mucin 5AC (MUC5AC) and mucin 6 (MUC6) that had a greater expression in severe asthma compared to health in peripheral airways but failed to attain significance (nominal p-value < 0.05; data not shown).