This study provides insights into the pathobiology of pulmonary fibrosis through single-cell transcriptomic analysis of human and mouse lungs. The research involved detailed tissue processing, cell sorting, and RNA isolation techniques to generate single-cell RNA-Seq data. Key findings include the identification of diverse cell populations in both normal and fibrotic lungs, including rare populations, and the analysis of Wnt signaling pathways. The study also compared bulk and single-cell RNA-Seq data, highlighting the importance of single-cell resolution in understanding cellular heterogeneity. Additionally, the research explored the expression of Wnt ligands and their targets in alveolar type II cells and alveolar macrophages, and the coexistence of different cell types in fibrotic lungs. The findings contribute to a deeper understanding of the complex cellular interactions and molecular mechanisms underlying pulmonary fibrosis.This study provides insights into the pathobiology of pulmonary fibrosis through single-cell transcriptomic analysis of human and mouse lungs. The research involved detailed tissue processing, cell sorting, and RNA isolation techniques to generate single-cell RNA-Seq data. Key findings include the identification of diverse cell populations in both normal and fibrotic lungs, including rare populations, and the analysis of Wnt signaling pathways. The study also compared bulk and single-cell RNA-Seq data, highlighting the importance of single-cell resolution in understanding cellular heterogeneity. Additionally, the research explored the expression of Wnt ligands and their targets in alveolar type II cells and alveolar macrophages, and the coexistence of different cell types in fibrotic lungs. The findings contribute to a deeper understanding of the complex cellular interactions and molecular mechanisms underlying pulmonary fibrosis.