A 2000 study called The Hallmarks of Cancer is the most-referenced paper in the journal Cell, one of the most influential journals in the world. Turns out that paper might be wrong.
And that might partly explain why cancer death rates are falling slowly.
The theory, which is illustrated in the video above, basically says that sometimes cells lose their ability to regulate growth and go crazy, creating cancer tumours. The New York Times reports that at the recent annual meeting of the American Association for Cancer Research in Orlando, Florida, scientists had a whole lot of other theories up their sleeves.
One states that microbes, which include tiny creatures like bacteria and make up 90 per cent of the cells in our body, sometimes turn against us to cause cancer.
Another theory is that what scientists used to think was "junk DNA" and makes up 98 per cent of our DNA (only two percent is the kind that actually instructs genes) is not junk at all but a mechanism for causing cancer, among other things.
Lastly, micoRNAs might be the culprit. Until recently scientists thought they didn't do much, but now they're starting to think that microRNAs might intercept or block messages from DNA to messenger RNA.
If all of that seems crazy-complicated, check out this pretty awesome video the New York Times created for you.
Of course, cancer ain't talkin' so these theories might be totally wrong too. But one thing's for certain: smoking is still bad. Damn.