Now, notice, because the plasma contains this insertion inside the green gene, this green gene is now inactivated. But because the blue gene does not contain any insertions, it still is able to actually produce that protein. That gives the cell the ability to resist the antibiotic tetracycline. And that can be a very useful procedure. For example, we can use this as a marker to basically differentiate between those cells that did not take up the plasmid and a cell that did take up the plasmid. So let's suppose we have a bunch of cells in our solution and we essentially introduce this plasmid into our cells.