With viral infections other than coronavirus, most studies have found that mice are superior to hamsters for studying viral lung injury, and distal airway epithelial cells can be a source of regenerating pneumocytes derived from cytokeratin 5-immunoreactive stem cells forming structures called nascent pods.35 As the distal airways of mice and humans have different structures, it has been postulated that this may lead to a different response in mice than in humans.4,27 There has been limited study on the role of non-ciliated cells contributing to lung damage in hamsters.36 This evidence concerns the gene KRT5 and viral infectious disease.