http://mobile.nytimes.com/2016/01/29/health/how-skin-cancer-develops-melanoma-zebra-fish.html?_r=2&referer=http://blog.dana-farber.org/insight/2016/02/the-cell-that-caused-melanoma-cancers-surprise-origins-caught-in-action/
Key points:
The prevailing idea about the development of a cancer is that genes randomly mutate in a healthy cell, perhaps from sun exposure, perhaps from simple bad luck. The mutated genes drive aberrant cell growth, and the growing mass of cells accumulates more and more mutations that drive it to grow faster and spread until, finally, a cancer is formed.
Yet researchers keep finding cancer genes in perfectly normal, healthy cells that never turn malignant.
More and more data suggest that just having mutations is not sufficient to cause cancer,” said Dr. Kornelia Polyak, a breast cancer researcher at the Dana-Farber Cancer Institute.
There has to be an additional event,” Dr. Zon said.