A further finding of the present study is the essential role for the MAPK SAPK/JNK in the IFN-ab induction by Ads in vitro and in vivo, although the DNA-mediated cytosolic induction of IFN-ab has been reported to be independent of MAPKs activation [14, 15, 36] . A cytosolic dsDNA-signaling pathway, mediated by the RNA helicase RIG-I and MAVS, and leading to the induction of IFN-b has been recently demonstrated in human hepatoma cells [84] . This induction pathway is absent in murine systems [22, 37, 84, 85] and is therefore unlikely to participate in the IFN-ab response of Ad-infected mice.