Cancer: most of people never get one

''Every year, millions of people are diagnosed with cancer - a remarkably high number. But what about the flipside of those statistics? That is, two out of three people never get cancer, and more than half of heavy smokers don’t get cancer, either. A recent study points out this overlooked fact, and suggests that researchers might discover something by asking why so many people are resistant to the often deadly disease.
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Klein and his coauthors identified five kinds of anticancer mechanisms. The first type is immunological, which applies to virus-associated cancers.
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The second mechanism is genetic, and the most common example is DNA repair mechanisms.
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The third mechanism is epigenetic, which involve changes in gene expression, rather than changes in the DNA text itself.
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The last two anticancer mechanisms are intracellular and intercellular. As part of an intracellular defense, a cell can trigger apoptosis, or cell death, if it detects extensive DNA damage, so that the cell doesn’t reproduce and spread the damage.'' [source]