in 1922. He then did post-doctoral work at Johns Hopkins School of Medicine and Harvard University. University of Rochester Warren joined the faculty of the Department of Radiology at the University of Rochester School of Medicine in 1926, becoming an Assistant Professor of Medicine. The department was a new one that had only been founded in 1921, based upon the ideals of medical education propounded by Abraham Flexner in his 1910 Flexner Report. The medical school had opened in 1925 and did not graduate its first class until 1929. Warren was one of the original group that Dean George Whipple assembled to staff the new medical school. At Rochester, Warren investigated the effects of artificial fever, including its possible use for treating gonococci infections. He was also interested in radiography. In 1930, Warren became an Associate Professor of Medicine. That year he published "A Roentgenologic Study of the Breast". X-ray imaging of the breast had first been investigated by Albert Salomon at the University of Berlin in 1913. He produced images of over 3,000 mastectomy specimens, and observed different forms and stages of cancer. He was even able to detect an undiagnosed cancer in a breast that had been removed because of a large cyst. However, Salomon apparently did not appreciate the life saving potential of his observations. Warren used radiology to track changes in breast tissue as a result of pregnancy and mastitis. He developed a stereoscopic technique, using patients rather than specimens and adapting general purpose X-ray equipment to his needs. His method involved having the patient lie on her side with one arm raised while being X-rayed. In 119 women who subsequently underwent surgery, he correctly found breast cancer in 54 out of 58 cases. This represented a leap forward, as it made diagnosis of breast cancer possible without surgery. It also sparked intense interest in the technique around the world. Today mammography saves thousands of lives. Manhattan Project In February 1943, Warren met with Dr Albert K. Chapman, the vice president and general manager of Eastman Kodak, Brigadier General Leslie R. Groves, the director of the Manhattan Project and Colonel James C. Marshall, the commander of the Manhattan Engineer District (MED). They asked him about his work with radiation and isotopes and asked Warren to become a civilian consultant for the MED. In March 1943, Warren met with Major Hymer L. Friedell at the MED's New