So, for instance, if our blood level glucose is very low, then what these liver cells will do is they will break down the glycogen as we'll talk about in a future lecture, into Glucose release the glucose inside the Blood. And that will increase the level of glucose to the correct level. So cells such as liver cells can use glycogen to regulate blood glucose levels of the body. This is important because cells such as brain cells depend almost entirely on glucose for energy. Now, what about skeleton muscle cells? Because not only do liver cells store glucose as glycogen, but our skeleton muscle cells also store the glycogen.