I think if you talk to the experts in any field where you have to take on a unknown challenge, where you're going to be working on it for a long time you'd find that to work themselves up to their best performance and really throw themselves into it, you know, spend all these hours in there and ah, give it their... give it their best that optimism plays a role.

The more you learn, the more you have a framework that the knowledge fits into.

So not only are we saving lives now, we're creating the incentive for the breakthroughs that over the next generation will mean we can take AIDS, malaria and TB and bring those numbers dramatically down.

Like a human being, a company has to have an internal communication mechanism, a "nervous system", to coordinate its actions.

This social-networking thing takes you to crazy places.

The two areas that are changing... are information technology and medical technology. Those are the things that the world will be very different 20 years from now than it is today.

I don't think I would have spent time learning about the immune system if understanding vaccines weren't something I considered very important.