KRT5 and idiopathic pulmonary fibrosis: Peripheral IPF lung tissue was cut in small pieces and placed in cell culture dishes containing an epithelial cell specific growth medium (Cnt-PR-A) as illustrated in Fig. 2A. Outgrown alveolar BC expressed high levels of TP63 (gene name of the p63 protein), KRT5, KRT14, and KRT17 on the RNA (Fig. 2B) and protein (Fig. 2C) level.