The advantage of molecular messaging over other sorts of communication, he says, is its ability to be deployed in hard-to-reach places, such as providing in-body communications for medical applications. The body's cellular signalling pathways have already been mapped, so these could serve as "communications channels”, says Dr Bush. Digital signals could be sent, say, to the vagal system to help moderate a patient's blood pressure or heart rate. Data transmitted molecularly might also enable blood-sugar levels to be monitored without invasive pinpricks.