Dr. Livingston was an internationally recognized expert on genes that regulate cell growth in the body - genes that, when they go awry, can lead to cancer. These genes are called oncogenes and tumor suppressor genes. Through his research, Dr. Livingston uncovered detailed biochemical steps required to initiate and maintain the transformation of these cells into tumor cells. His focus was on the regulatory controls of signal transduction - the smooth and coordinated flow of special chemical signals from the surrounding environment to the cell, where it is transduced into specific commands that tell cells whether or not to grow - and their role in cancer development. In recent years, his work centered on those key molecular steps that trigger the development of breast and ovarian cancer. Dr. Livingston was the recipient of numerous awards and honors. He was been elected to the Institute of Medicine of the National Academy of Sciences, the National Academy of Sciences, itself, and the American Academy of Arts and Sciences. He sat on multiple editorial boards, the science advisory boards of other research institutions, and was a member of the Association of American Physicians, the American Society for Clinical Investigation, the American Society for Microbiology, and the American Academy of Microbiology. He was also a Foreign Associate of the European Molecular Biology Organization and served as Vice Chair of the Board of the Damon Runyan Cancer Research Foundation. Dr. Livingston authored more than195 scientific publications.