CLDN1 and idiopathic pulmonary fibrosis: Our scRNAseq data demonstrate increased expression of the stress-induced keratins KRT6 and KRT1727, upregulation of key molecules of epithelial barrier function (claudin 1 and 4), of several integrins which regulate ECM composition (β6, να, β1, α6, and α2), markers of epithelial cells senescence such as GDF1528, and the EGFR ligands AREG and HBEGF in IPF-ABCs.