In addition, in the epithelium from bronchi, and proximal and distal bronchioles a higher MUC5B and MUC5AC expression by secretory cells, as well as a minor number of ciliated cells, linked with an increased ciliary length were observed in IPF patients, which suggest that mucus hypersecretion and ciliary impairment in conducting airway are involved with the alveolar injuries in IPF patients [35]. This evidence concerns the gene MUC5AC and idiopathic pulmonary fibrosis.