Not all inflammation leads to pain. Despite widespread infection followed by fever, colds rarely cause pain. But when some cytokines and certain immune cells are active near pain-sensing nerves, they trigger receptors that convey pain sensations to the brain.
Near the turn of the millennium, James Collins and Stanislas Leibler independently undertook rather similar projects: design what would become synthetic biology’s seminal genetic circuits. And they came up with strikingly similar action plans.