As shown in Fig. 2 (C–E′) and Table 1, we found that PKD1 was expressed with a weak to strong intensity in regenerative AECs lining remodeled fibrotic alveolar septa and fibroblast foci in 75% (9 of 12) of IPF subjects examined. The gene discussed is PKD1; the disease is idiopathic pulmonary fibrosis.