 Using this system, Kornberg made the major discovery that transmission of gene regulatory signals to the RNA polymerase machinery is accomplished by an additional protein complex that they dubbed "Mediator".As noted by the Nobel Prize committee, "the great complexity of eukaryotic organisms is actually enabled by the fine interplay between tissue-specific substances, enhancers in the DNA and Mediator.The discovery of Mediator is therefore a true milestone in the understanding of the transcription process."