In addition, it has been widely observed that airway epithelium consisting of p63+ cytokeratin-5/KRT5+ positive basal cell sheets (underneath luminal-ciliated bronchial cells) overlie the fibroblast foci, indicating that the integrity of the alveolar epithelium is severely disrupted in IPF [10,13]. The gene discussed is KRT5; the disease is idiopathic pulmonary fibrosis.