"Oh, yeah. A blueprint is like a plan for how to build something. A building or a bridge or whatever. It tells the builder how to make the thing the designer had in mind."

She considers Herian's example, and nods. "But yeah. I mean, it's very possibly both? Say you and someone with different parents were fed the same diet - they may never be able to get as tall as you. But if you went hungry a lot as a kid, you might not reach your full potential height, either."

Cosima shrugs a little. "So my field - one of its practical uses - is trying to pinpoint what causes people who are born sick to be that way, so maybe we can develop ways to help them."