Aplastic anemia is an ancient disease. The first patient was recorded by the young Paul Ehrlich in 1885; Vaquez coined the term "anemia aplastique" in 1904; and Cabot and other pathologists detailed its clinical symptoms in the beginning of the 20th century. In the current period, an almost consistently deadly prognosis, mostly for young people with abrupt acute pancytopenia, has been reversed, with the introduction of viable treatments for almost all patients. In the research laboratory, understanding of pathophysiology has guided therapy development. Marrow failure syndromes have been linked to viral infections and environmental pollutants, inherited and acquired genetic abnormalities, early leukemogenic events, and normal aging hematopoiesis.