[Advances in Classification and Research Methods of Lung Epithelial Stem 
and Progenitor Cells]

Isolation and characterization of lung epithelial stem and progenitor cells and understanding of their specific role in lung physiopathology are critical for preventing and controlling lung diseases including lung cancer. In this review, we summarized recent advances in classification and research methods of lung epithelial stem and progenitor cells. Lung epithelial stem and progenitor cells were region-specific, which primarily included basal cells and duct cells in proximal airway, Clara cells, variant Clara cells, bronchioalveolar stem cells and induced krt5+ cells in bronchioles, type II alveolar cells and type II alveolar progenitor cells in alveoli. The research methods of lung epithelial stem and progenitor cells were mainly focused on lung injury models, lineage-tracing experiments, three dimensional culture, transplantation, chronic labeled cells and single-cell transcriptome analysis. Lastly, the potential relationship between lung epithelial stem and progenitor cells and lung cancer as well as lung cancer stem cell-targeted drug development were briefly reviewed.