We constantly review the scientific evidence as it comes out. I would say that on this particular issue there's new evidence very regularly that is starting to suggest certain directions, but I don't think anybody would say that we have the weight of evidence yet to be conclusive on any of these key issues. There are a few issues where it is conclusive, and the dangers of nicotine is one of them.
I'd like to turn to Dr. Stewart for a moment to talk about nicotine and our approach to the evidence in making these kinds of decisions.