How does a blood cell know it’s not supposed to be a nerve cell? Why don’t the cells that generate heart muscle build skin instead? After all, every single cell in the human body has the identical genetic makeup.

That mystery was unraveled by Brooklyn-born Hebrew University Prof. Howard (Chaim) Cedar, who on March 25, 2012 added a $50,000 Rothschild Prize to his long list of accomplishments.

“I am always very excited when our work is recognized,” Cedar tells ISRAEL21c the morning after the ceremony. “The fact that people got together and decided what we’re doing is something important is wonderful.”

Colleagues from Hadassah-Hebrew University School of Medicine came to cheer him on – most notably his longtime lab and lunch partner, Prof. Aharon Razin – as well as his wife, children and grandchildren.

Cedar’s eldest son Joseph is an acclaimed Israeli filmmaker who has twice been on the short list for an Academy Award.

Like the fictional father in Joseph Cedar’s Oscar-nominated Footnote, the senior Cedar won the prestigious Israel Prize (in 1999) and is a member of the Israel Academy of Sciences and Humanities. “It’s a big joke in our family,” Cedar says amiably. “We don’t understand how it turned out that two people in same family seem to be getting awards.”

Out of the public spotlight, Joseph’s siblings are accomplished in their own right. Dahlia, like her mother, is a psychodrama therapist and teacher. Noa, an epidemiologist, also sells seeds, nuts and dried fruits in Jerusalem’s Machane Yehuda market. Yoav, trained in special education, recently switched to social work. Yonatan is a piano teacher and accompanist, and university student Daniel guides groups such as Birthright.

Representing the Jewish people

Joseph was just five, and Dahlia two, when Howard and Zipora Cedar moved to Israel a fortnight before the 1973 Yom Kippur War. Cedar had already earned the distinction of having been the first American to complete a government-sponsored MD-PhD Medical Scientist Training Program at New York University.

He and his wife met in 1966 and were enthusiastic about living in Israel. “I am a little infected with the idea that part of being Jewish is contributing to the world, and coming here meant I would be able to represent the Jewish people in whatever I do,” says Cedar.

The previous summer, while in medical school, he’d worked for a month in a Hebrew University lab. During a two-year stint at the US National Institutes of Health — an obligation in return for being exempted from serving in Vietnam in order to complete his schooling — he contacted the lab director and secured a position and temporary housing in Jerusalem.

Now 69 and still biking six miles to work every day, Cedar is officially retired but actively collaborating on experiments to learn even more in the field he founded, epigenetics. This discipline examines how, when and why the genes inside body cells become specialists despite being identical to one another.

“It involves a lot of controlled orchestration,” Cedar explains.

Over the course of 20 years, he and Razin discovered that though everybody’s DNA shares a common “text,” a chemical process called methylation “annotates” the text to give the genes specific marching orders. Methylation explains why a nerve cell never turns into a skin cell. And it also explains something fundamental about cancer.

“When cells undergo change, it’s not a change in text but in annotation,” Cedar says. “If we can control the annotation we could make a big contribution to alleviating, preventing, diagnosing and treating cancer.”

This is the focus of Cedar’s current research at the medical school. Meanwhile, centers dedicated to practical applications of epigenetics are popping up across America and Europe. “Israel is a partner in that,” he says proudly. “We are one of the leaders in epigenetics because the field was born here.”

One of the major areas that intrigues scientists is how agriculture could benefit from controlling methylation of plant DNA. Another is the role of methylation in stem-cell harvesting and manipulation.

“The field will have an impact in many years,” Cedar predicts. “It’s just beginning. We have a lot to learn and there’s a lot of potential.”