You just have to step into your local chemist to see how far medicine has come over the past 100 years. Life changing drugs, which were once unthinkable – like antibiotics, insulin and the contraceptive pill – are now commonplace. But there’s still so much we don’t know about the medicines we take. Consider your average pack of Paracetamol pills; we know these work to cure headaches and pains, we know they’re relatively harmless when taken in small doses, but scientists still don’t really know how they work. And if we don’t know how existing drugs work, how can we design better ones?