severe emphysema at birth as a result of disorganization of the Golgi apparatus and formation of aberrant vesicular structures within club cells. Malignant club cells are also seen in bronchioalveolar carcinoma of the lung. Serum club cell proteins are used as a biomarker of lung permeability. Exposure to particulate air pollution may compromise the integrity of the lung epithelium and lead to rapid increase in epithelial barrier permeability, as reflected by increased serum club cell concentrations. History Club cells were previously called Clara cells, as they were first described by Max Clara (1899–1966), in 1937. Clara was an active member of the Nazi Party and used tissue taken from executed victims of Nazi Germany for his research—including the work that led to his discovery of Clara cells. In May 2012, the editorial boards of most of the major respiratory journals (including the journals of the American Thoracic Society, the European Respiratory Society and the American College of Chest Physicians) concluded that the continued use of Clara's eponym would be equivalent to honoring him; they therefore introduced a name-change policy, which went into effect beginning January 1, 2013. The term "Clara" was used parenthetically after "club cell" for a 2-year period, after which "Clara cell" and "Clara cell secretory protein" were conclusively replaced with "club cell" and "club cell secretory protein", respectively. See also cGMP-dependent protein kinase List of medical eponyms with Nazi associations Skatole List of human cell types derived from the germ layers References External links Histology at ucsf.edu Lung anatomy Surfactant secreting cells Animal cells Human cells Nazi human subject research