I think the critical question is: What are the possible fates of
mutagens which enter a cell. How many bind harmlessly and leave without
damaging ? How many bind to junk DNA ? How many bind to exons? How many
bind to introns? The binding sites of certain mutagens are quite
specific when we are refering to the cancer causing results. But only if
we can assess the frequencies of these other fates can we be sure of the
My 'contention' that introns help prevent these cancer causing mutations
was based on certain guesses which may turn out to be wrong. But if
these frequecies are known, and can be used to argue against my
position, I would certainly be willing to acquiesce.
Any such help would be appreciated. And I do admit that my 'contention'
was worded a bit too strongly.