He was in auto mechanic school when he was drafted into the military in 1940, two years before the Japanese attack on Pearl Harbor. He worked as a mechanic, but was eventually assigned to the all Japanese-American 442nd Regiment, which became the most decorated unit for its size in the U.S. Army during World War II. He was an artillery spotter and rose to the rank of lieutenant. Ito participated in the famous rescue of the "Lost Battalion", a unit of the 36th Texas Division which had been cut off and surrounded by the Germans. Though the 442nd suffered extremely heavy casualties in the engagement, Ito emerged unscathed. His unit, the 552nd Field Artillery, later liberated a subcamp of the Dachau concentration camp.
After the war, he attended university on the G.I. Bill, eventually earning a PhD in Biology from Cornell University. Ito’s research career was stimulated by a summer in Woods Hole at the Marine Biological Laboratory in 1951, where he met scientists such as Otto Loewi, and particularly Katsuma Dan. He became a professor at the Harvard Medical School Anatomy Department in 1961, where his research centered on ultrastructural (electron microscopic) studies of the gastrointestinal system. In the early 1980s, he and William Silen showed that repair of the mucosal lining of the stomach (“gastric mucosal restitution”) is a far more rapid process than previously thought possible. Thomas D. Pollard began his studies of acto-myosin based cell motility as a student in Ito’s lab. Although Ito retired in 1990, the Harvard Medical Emeritus professor was still active in the lab as of 2010.
On October 5, 2010, President Obama signed a bill awarding the Congressional Gold Medal, the highest civilian U.S. medal (along with the Presidential Medal of Freedom), to the members of the 442nd Regiment and other units for the rescue of the Lost Battalion.
- "Susumu Ito". goforbroke.org. Retrieved November 2, 2011.
- Landau, Misia (1998). "The Long March Of a Soldier-Scientist".
- Jose Santos (November 1, 2011). "Harvard professor among veterans to get Congressional Gold Medal". CNN. Retrieved November 2, 2011.
- "Japanese-American Army units from World War II honored". CNN. October 5, 2011. Retrieved November 2, 2011.
- WGBH / PBS program about Susumu Ito