Until recently innate immunity was viewed as the poorer relative of the sophisticated adaptive immune response. We now know, however, that these ‘higher’ immune responses are actually underpinned by an elegantly hewn system of innate immune surveillance. Discovered first by developmental biologists, again by immunologists, and even by sociologists, Toll receptors have revolutionized our understanding of innate immunology. Although a small part of a complex system, Toll receptor biology compels us to revisit existing models of self – non-self recognition.