Similarly, this occurred in the comparison between IPF patients without PJ and controls with PJ, in which we identified hemoglobin subunits alpha and beta, and keratin 1 as downregulated in the IPF group and upregulated in the control group with PJ, while the proteins phosphoglycerate kinase 1, alpha-1-antitrypsin, pulmonary surfactant-associated protein B and vimentin were regulated in antagonistic directions (Figure 1F and Table S1). Here, KRT1 is linked to idiopathic pulmonary fibrosis.