Philip I. Marcus (June 3, 1927 in Springfield, Massachusetts – September 1, 2013 in Farmington, Connecticut) was an American virologist and a leader in interferon research. From 2003 he was a Board of Trustees Distinguished Professor of Molecular and Cell Biology at the University of Connecticut. Early life and education Marcus was born June 3, 1927, in Springfield, Massachusetts, the son of Julius Marcus and Marley Spier (Sheffield, England), and the brother of Maxine Altshuler, and Emil Marcus. In 1945 he graduated Springfield Technical High School (which would later merge with Springfield Classical High School to form Springfield Central High School) the STEM system of its time. During World War II, while in high school, he worked at the great forges in the Springfield Armory immortalized by Longfellow's poem "The Arsenal at Springfield." He enlisted in the Army Specialized Training Reserve Program and was assigned in 1945 to attend the University of Connecticut in Storrs, Connecticut. Marcus received his education directly as a result of the G.I. Bill. After six months each at the University of Connecticut and the University of Maine (in Orono) he had earned two years of college credit. Assigned to active duty in the US Air Force and stationed in Istres, France, he rose to the level of staff sergeant within a year. The GI Bill enabled him to attend college, the first in his family to do so. He took some courses in general education and engineering while serving in the United States Army Air Force in 1945–46 then, after a year abroad as part of the US occupation forces in Europe, left the USAAF and studied for his BS in Bacteriology in 1950 at the University of Southern California, his MS in microbiology in 1953 at the University of Chicago (where he first met Leó Szilárd) and earned his PhD microbiology/biophysics in 1957 from the University of Colorado Medical Center, where he also was an associate professor and worked with Theodore Puck. Career While at the University of Chicago, he worked with Aaron Novick and Leó Szilárd and later with Paul Talalay. In Colorado, he became codiscoverer of the clonogenic assay and the feeder cell system, making it possible to grow clones from single mammalian cells as in stem cells. He was the first to clone the immortalized HeLa cells. That procedure led to the first determination of human cell sensitivity to X-rays. Over