In-the-dish vs in-the-body?

Stefanie - This is a classic problem in experimental genetics. You first have to be sure that your in vitro system is a very good one and you have various controls for that. Eventually, you have to see if the same thing is happening in vivo, but it's a good way to start off. Chris - So, start there and then build up. Because it's generally cheaper as well. Stefanie - Exactly, yes.