Nigel, you're missing the basic way in which cancers form. They're caused by cells failing to reproduce correctly due to a mutation in the cell. Mutations happen all the time - it's the reason evolution exists (if you're a member of the religious right, ignore that and pretend I said "it's the reason you can breed different varieties of living things", cos that discussion is off-topic). Mutations are caused by a cell's copying mechanism breaking down.

Now spontaneous mutations will always happen, because there's a certain element of randomness involved. But there are many chemicals which attack a cell's copying mechanism to prevent it making correct copies and only copying itself as needed. If a chemical has the effect of breaking a cell's copying mechanism so that it copies itself non-stop, that chemical is a carcinogen - it interferes with copying to produce cancer. The body still has some defences against this, but they're generally less effective, because the first line of defence is getting the copying right to start with.

To take an analogy, think of a tightrope walker. A good one can run up and down the rope with a miniscule risk of falling off. Now suppose you throw stones at the tightrope walker until they lose their balance and fall off. What you've done is taken a miniscule risk and applied outside influences to increase that risk until the disaster happens. And this is precisely what carcinogens do to cell reproduction - they take an existing small possibility and greatly increase the chance of it happening.

Regarding the guy running the website being a "fruitloop", I have to agree. Not only does he claim that cigarettes actively *prevent* cancer, but he also claims that the Bali bombing was a "micro-nuke" planted by Israeli and US forces, and that the 9/11 hijackings were achieved via some remote-control system secretly installed into all airliners worldwide by US authorities.

Daylia, if you've spent weeks investigating this, I suspect you need to be reminded about Google. A simple Google search for "mouse lung cancer study smoking" came up with this link which is pretty conclusive: http://monographs.iarc.fr/htdocs/monographs/suppl7/tobaccosmoke.html. In other words, if this Prof Schrauzer says that this has never happened, either he was lying or all the people running the referenced studies were lying.

Graham.