That's too simplistic. Yes, there are many "random" processes affecting DNA, including transposons and viruses. But there are also tumor suppression mechanisms

That's too simplistic. Yes, there are many "random" processes affecting DNA, including transposons and viruses. But there are also tumor suppression mechanisms (genes), too. What the article talks about is the case when a cancerous outbreak goes unchecked in the human body. http://en.wikipedia.org/wiki/Cancer http://en.wikipedia.org/wiki/Cancer (Sorry for the RTFWP)