The innate signaling of dangers and the dangers of innate signaling.

The innate immune system of mammals has been forged by coevolution with microbes in response to the double constraint of preserving a symbiotic interaction with commensal flora and eliminating intrusion of those commensals or invasion by pathogens. Thus, a 'sensing' network, accompanied by or lacking inflammatory responses, is controlled by elaborate mechanisms of regulation that maintain balance in the basal state. A growing number of non-Toll-like innate immune receptors is recognized as part of this surveillance network.