IL18 and pulmonary fibrosis: Cell-cell communication based on ligand-receptor analysis of scRNAseq data from bleomycin-instilled lung fibrosis models, revealed the most potent communication in the pleura during fibrosis occurred between monocyte-derived AMs (Supplementary Fig. 5b) and mesothelial cells, through IL-18R on mesothelial cells and IL-18 on AMs (Supplementary Fig. 5c).