MUC5AC and chronic obstructive pulmonary disease: Taking strength from our previous characterisations of bronchial epithelial remodelling features in COPD patients [3, 6, 7], we then tested the associations of peribronchial inflammatory cell accumulation with eight potential readouts of COPD‐induced epithelial alterations [epithelium height, proliferation, basal cell count, multiciliated cell surface, primary ciliated cells, mucous‐secreting cells (MUC5ac and MUC5b) and CC10‐secreting cells].