Abnormally increased levels of a mucus protein called MUC5AC are associated with airway inflammatory responses and exacerbation severity in people with COPD, suggests the findings of a recent study published in The Journal of Clinical Investigation. A team of international researchers, who  analysed lung mucus samples from COPD patients and healthy people in mouse models as well as lab-grown human lung cells to assess the role of abnormal mucin secretion in COPD exacerbations.  The study revealed that the virus-induced MUC5AC itself plays a central role in driving airway inflammation and exacerbation severity in COPD and MUC5AC could be a potential therapeutic target to lessen exacerbations in this patient population.