I don't believe there's any published evidence, at this point, about other substances being vaporized through the traditional electronic cigarette, but there's certainly lots of anecdotes about marijuana oil. So, you may well be right. This may well become a vehicle for other things, and we may have other considerations at that point.
But just to answer the propylene glycol issue, it's certainly used in lots of things, and the proponents of these cigarettes would say that we use it in lots of things and it's harmless. But nobody actually, I would suggest, knows the answer to what chronic inhalation of propylene glycol will mean. We'll get that answer in about 10 years, or whatever. Right?