Prof. Ben-Ami Sela has made a habit of shaking things up. Born and raised in Tel Aviv, the director of Sheba Medical Center's institute of chemical pathology and a member of the biochemistry department at Tel-Aviv University (TAU) spent a lot of time as a child preparing fancy chemical mixtures at home - "some of which were rather explosive, to the dismay of my parents and neighbors." Although he never wanted to be a physician, he achieved his childhood dream of becoming a chemist, and uses the knowledge not only to find ways to fight disease but also to warn patients, other researchers and the general public about the dangers of tobacco, and inform them how to lower the risk for heart disease and cancer. He has written more than 250 articles in his field, but he is no less proud that he has composed over 800 articles on biology and medicine published on various Internet sites - over 500 of them on Teva Life (www.tevalife.com), where Sela is recognized as a "dedicated teacher and preacher." Now Sela has written a 278-page Hebrew volume about the latest in cancer called Mahalat Hasartan: Havanot Hadashot, Trufot Hadashot, Metzukot Yeshanot (The Disease of Cancer: New Understandings, New Medications, Old Concerns). Published by Sadeh Ltd., the NIS 88 soft-cover volume would make a perfect textbook for medical students. But even though it contains a lot of medical terminology including genetics and drug names, he targets the general public, especially those touched by cancer. "I WROTE the book in a rather semi-professional format for medical students, doctors and people affiliated with the medical profession, but also to the general public, even though not all laymen may be intimately acquainted with the terms used," he comments. "Although I have spent many years writing and lecturing to the public, one tends to underestimate their knowledge. The Internet, with its Google search engine and Wikipedia encyclopedia, has done a great service in getting people to understand various theories and facts. I get quite a few e-mails and phone calls from people with remarks and questions related to my articles, and I am amazed at their level of knowledge." Since 1993, he has been an active participant in the Israel Forum for the Prevention of Smoking, and delivered over 200 lectures to high-school pupils, soldiers, teachers, psychologists and others on the evil of smoking. He is also a member of the National Council for Health Promotion, and a consultant on lung cancer to the Israel Cancer Association. AFTER EARNING his master's degree in microbiology and biochemistry at TAU, Sela went to the Weizmann Institute in Rehovot to work with eminent genetics Prof. Leo Sachs, where he studied the biochemical changes found on the surfaces of various cancerous cells. Studying and working with Sachs, regarded as one of the "fathers" of Israeli scientific research, Sela was awarded his doctorate. In 1974, he went to Rockefeller University in Manhattan as a post-doctoral student, working in the lab of Prof. Gerald Edelman, the Nobel laureatee. There he spent three years investigating the immunological nature of carbohydrates and glycolipids. "These molecules," Sela explains, "happen to contribute to the antigenic fingerprinting of cancer cells." Upon returning to the Weizmann Institute in 1977 and later moving to TAU, he tried to prepare antibodies to specific carbohydrate antigens that are exclusive to tumor cells, and use the antibodies to attack malignant cells without affecting adjacent normal cells. At Sheba in Tel Hashomer, he also investigated a variety of subjects from cardiovascular and metabolic diseases to the definition of new markers for malignancy. Sela was determined not to remain in the ivory tower of research, so when he arrived at Sheba 20 years ago, he became "deeply involved with the humane part of the cruel aggregate of symptoms of cancer. On a daily basis, I discuss individual cancer patients. Following up these cases, meeting with the patients - sometimes for long periods of time - and seeing people who faced the unfortunate epilogue of their lives - I was deeply influenced. Only when you actually deal with cancer patients do you realize the immense dimensions of cancer." He noted with a twinkle in his eye that as he is not a physician, his "largest contribution to public health" is that he raised his younger son Yaron to become a "real" doctor, and he is now a practicing orthopedic surgeon at Sheba. AFTER HAVING written three books - one on homocysteine (a molecule whose elevated levels are a powerful risk factor for cardiovascular disease), another on the significance of lab tests and a third on heart disease, the volume on cancer is his fourth. "Cancer" is a misleading word, as it represents over 80 diseases, depending on the part of the body affected. With all the subtypes and borderline situations, the total can reach 200. But all of them have two things in common, Sela writes. These are "the pace of uncontrolled division of cells that change and become malignant, and the ability of these cells to invade healthy tissues and damage them - even if these tissues are distant from where the original tumor was created." Cancers that originate in the epithelial tissue that covers the outside of the body (skin), internal organs and glands are called carcinomas; those that originate in supportive tissues such as bone, muscle and blood vessels are sarcomas; while blood cancers are leukemias (affecting blood cells) or lymphomas (affecting the lymph glands), and nerve cancers are gliomas. Sela quotes biology Prof. David Baltimore, the Nobel laureate at the California Institute of Technology, as saying that the more we understand the significance of cancer, the more we know how far we are from being able to provide answers to this biological phenomenon. The average adult human body, Sela continues, contains about 100 trillion cells, and about half a million die every second. New cells are produced in their place, the result of cell division that preserves the DNA inheritance from each mother cell. Could it be that this massive activity of copying DNA can be carried out without mistakes? Surprisingly, thanks to evolutionary processes (or divine planning), every cell is equipped with enzymes whose role is not only to copy genetic material but also to carry out "proofreading and editing" and even to correct errors in the DNA meant for new cells. But even this sophisticated mechanism cannot prevent some errors from taking place. CANCER OCCURS when the sequence of nucleotides that constitute the DNA in a certain gene undergoes change that cannot be repaired. This mutation occurs more frequently when the cell has been exposed to radiation, certain drugs or carcinogenic chemicals, or when a segment of nucleic acid of an oncogenic virus penetrates a cell's DNA. These factors may make the DNA sequence in the gene detach, open and reattach in an erroneous way, creating oncogenes that trigger cancer, while other genes meant to prevent cancers (cancer suppressors) are neutralized. Fortunately, writes Sela, the start of cancer usually requires several years of exposure to carcinogens such as tobacco smoke, ultraviolet rays or asbestos. If cancer cells are removed when they are isolated in one spot, that can be the end of the disease, but if the tumor sends out metastases to other parts of the body, it can be much more deadly. ABOUT A quarter of a century ago, the US government declared a "War on Cancer," but it is still with us, and more than half million Americans (and many thousands of Israelis) die from it every year, with the toll second only to that of cardiovascular disease. Without a major breakthrough, Sela notes, one in every four Americans living today will eventually die of cancer. "Like Jason who spent a whole life chasing the Golden Fleece, cancer researchers are still looking for the magic bullet - a drug or an antibody that would hurt the tumor cell and not the normal healthy cell adjacent to it. We're getting closer to that goal, but since cancer cells are so elusive, progress is slow." Lung cancer is the leading killer, followed by colorectal, breast and prostate cancer, making "smoking the single most obvious preventable cause of various cancers that stupid people inflict upon themselves." Eighty-seven percent of lung cancer, 91% of pharynx and esophageal cancers and a significant percentage of pancreatic and bladder cancers are brought about by carcinogens found in cigarettes, says Sela. "In a country with a health minister [Ya'acov Ben-Yizri] who smokes, a country reluctant to impose anti-smoking laws, raise taxes on tobacco products, prohibit smoking ads in the papers and get cigarette vending machines out of hospitals - in such a country it will be tougher to curb the rate of rampant cancer," he says, his pleasant and humorous nature mutating to rage.