Now, the thing about these enhancer regions is they can be found either upstream to the left or downstream to the right with respect to where that eukaryotic gene is found. And these enhancer sequences are found very far away from that eukaryotic gene, usually thousands of nucleotides away. So in this particular case, this is 1000 nucleotides away from this eukaryotic gene. So we see that the RNA polymerase travels very quickly along our DNA molecule until it locates these promoted regions at which it binds onto the promoter region and it begins the process of transcription. It transcribes that bacterial cell and it uses the DNA molecule that is complementary to this DNA molecule that is shown here. Now, the question is, how does it know when to stop that transcription process?