KRT5 and idiopathic pulmonary fibrosis: Here, we show that, in striking contrast to normal lungs, distal IPF lungs present 1) an increased abundance of KRT5+ cells, 2) the emergence of a frequent KRT5+KRT14+ subpopulation, 3) morphological changes in these basal cells, and 4) the existence of characteristic patterns of KRT5+KRT14- and KRT5+KRT14+ structures.