We identified a special population of fibroblasts that highly expressed extracellular matrix-related genes, POSTN, CTHRC1, COL3A1, COL5A2, and COL12A1. We propose that the close interaction between ECs and fibroblasts through ligand–receptor pairs may have a critical function in IPF development. This evidence concerns the gene COL12A1 and idiopathic interstitial pneumonia.