Sarah Elizabeth Stewart, MD, PhD
Dr. Sarah Elizabeth Stewart (August 16, 1905-November 27, 1976) was a Mexican-American researcher who pioneered the field of viral oncology research. She was born on August 16, 1905 in Tecalitlán, Jalisco, Mexico.  She did her undergraduate work at the New Mexico State University graduating with a Bachelors of Science in 1927. She went on to earn a master’s degree from the University of Massachusetts Amherst in 1930. In 1935, she began working at the National Institutes of Health (NIH) completing a Ph.D. in microbiology from the University of Chicago in 1939.
In 1944, Stewart sought to study the link between animal tumors and viruses. Unconvinced, NIH executives rejected her proposal. Subsequently she resigned from the NIH and came to Georgetown University as a faculty member, teaching microbiology at the School of Medicine. She was encouraged to complete her M.D. and in 1949, she became the first women to be awarded a Doctorate of Medicine from Georgetown University School of Medicine. 
In 1951, having completed an internship, she returned to NIH to work with her colleague Dr. Bernice Eddy. Stewart and Eddy developed an interest in researching viral links to cancer based on the pioneering research of Jonas Salk, whose work led to a vaccine for the virus which caused polio. In 1953, Stewart and Eddy were among the first to discover the cancer-causing, or polyomavirus.  Though, it wasn’t until 1958 that Stewart and Eddy were successful in growing the virus which now bares their names, the SE (Stewart-Eddy) polyomavirus. Stewart and Eddy were the first to successfully demonstrate, through Koch’s postulates, that cancer-causing viruses could be spread from animal to animal. 
As a result of their work, Stewart and Eddy were nominated twice for the Nobel Prize. In 1965, President Lyndon B. Johnson presented Stewart with the Federal Women’s Award for her contributions to the field of cancer research.
In 1971, Dr. Stewart returned to Georgetown as a full professor to teach in the department of pathology. Shortly thereafter, she retired to New Smyrna Beach, Florida where, on November 27, 1976, she died of the disease she fought so hard to study.
Wikipedia- Sarah Stewart, MD, PhD- February 2009
Cancer Research, Sarah Stewart, Obituary, Volume 37, 4675
Stanley, Autumn. Mothers and Daughters of Invention, Page 165. 1993, Rutgers University Press.
Smith, J.Y. (1976-12-08). “Dr. Sarah Stewart, Cancer Research, Dies”. The Washington Post: p.C15.