Systemic innate cytokine responses can play protective antiviral functions but can also lead to severe immunopathology when too high. Thus, the benefits of activation of pDC antiviral defenses must be balanced against the risks of immunopathology. In this respect, it is likely that mechanisms are in place to finely tune the activation of pDCs depending of the nature and intensity of the environmental threats that they can perceive. The existence of such mechanisms is supported by the observation that certain autoimmune diseases including systemic lupus erythematosus (SLE) or psoriasis have been found to be associated with unbridled IFN-I production by pDCs [103] [104] [105] .