Given the immense heterogeneity within lung stromal cells at homeostasis and the dynamic changes in both surface markers and transcriptomic profiles that occur during fibrogenesis in other in vivo model systems (e.g., bleomycin) and human IPF (19, 21, 23, 24, 26, 27, 39, 40), we next performed scRNA-Seq on digested lung samples to assess transcriptional differences in specific mesenchymal subsets of the IER-SftpcI73T model in the presence and absence of PGF2α-Ptgfr signaling (Figure 5). This evidence concerns the gene PTGFR and idiopathic pulmonary fibrosis.