NOS2 and animal viral hepatitis: Beside PPARγ, IGF-R-signaling, through different upstream pathways, could trigger the activation of the transcription factor NF-κB [49] which likewise regulates COX-2 and iNOS and plays a role in viral hepatitis, chronic liver disease including fibrosis and cirrhosis and in HCC [24,50] and is spontaneously activated in HCC cells [22].