Using Mathematical Tools in Biology?

Mathematicians like to believe that they're being useful to scientists in other fields. But it's not always easy to find really good examples of where math has been helpful in the service of biology. So I appreciate hearing that this was one case where we did some good. Can I also just add one? Yeah, please. It's essential because even with the repressilator, which is only three genes, you can't intuitively reason about what the circuit's going to do. You really need these mathematical tools.