Well, instead of using prokaryotic genes, we can also use eukaryotic genes. And this is especially important in a field of medicine where in medicine we're able to use this procedure to basically synthesize any protein, any enzyme that we want to. And that's exactly what allows patients with, let's say, diabetes to essentially survive for a very long time because they now have a way to obtain these proteins which are synthesized in the lab via this procedure. Now, the major problem with this procedure or the initial problem that we had to solve when we were first developing this process was the following. Remember, eukaryotic mRNA molecules and prokaryotic mRNA molecules aren't the same in eukaryotic cells. The initial eukaryotic mRNA molecule that is synthesized contains introns and exons.