The Clara cell: a "Third Reich eponym"?

German anatomist Max Clara (1899-1966) described the "Clara cell" of the bronchiolar epithelium in 1937. The present article investigates Clara's relationship with National Socialism, as well as his use of tissue from executed prisoners for research purposes, details about both of which are largely unknown to date. Our methodology for the present study focussed on analysis of material from historical archives and the publications of Clara and his co-workers. Clara was appointed as Chair of Anatomy at Leipzig University (Leipzig, Germany) in 1935. He owed his career, at least in part, to Nazi support. He was an active member of the Nazi party (Nationalsozialistische Deutsche Arbeiterpartei (NSDAP)) and engaged in university politics; this included making anti-Semitic statements about other academics in appointment procedures. Nevertheless, he also supported prosecuted colleagues. Much of Clara's histological research in Leipzig, including his original description of the bronchial epithelium, was based on tissue taken from prisoners executed in nearby Dresden (Germany). Max Clara was an active and outspoken Nazi and his histological research exploited the rising number of executions during the Nazi period. Clara's discovery is thus linked to the Nazi system. The facts given in the present paper invite discussion about the eponym's neglected history and its continued and problematic use in medical terminology.