and this video, we're going to begin our introduction to cell cycle regulation. And so the cell cycle, which includes cell division, is actually really, really highly controlled and regulated. And so a cell is not supposed to divide whenever it wants. A cell is on. Lee supposed to divide whenever receives the appropriate signals for it to divide. And so cell division is really, really highly controlled and actually activated by a variety of cellular signals in the form of proteins called growth factors. And so growth factors can be defined as a biological substance that promotes cell division. And so once again, a cell is not supposed to divide whenever it wants. A cell is on Lee supposed to divide whenever it receives the appropriate signals that promote cell division. Now, in addition to the growth factors that contribute, er cell division, uh, there are also multiple cell cycle checkpoints that are also going to be very, very important in the regulation of the cell cycle. And so, as we'll move forward as we move forward in our course, we're going to talk more and more about the cell cycle checkpoints. But ultimately what these cell cycle checkpoints do is they kind of act like little stop signs for a cell. And so the cell will actually stop at these checkpoints. And so the checkpoints are going to prevent the cell from entering the next phase prematurely. And so the checkpoints are away for the cell to kind of stop and check to make sure everything is okay. Make sure that there are no errors before it proceeds into the next phase. And so if an error is actually detected at any checkpoint, then a protein called P 53 can actually either trigger repair of the air to try to fix the air. But if the air cannot be repaired, then the P 53 protein can also trigger another process called a pop toe sis. And so apoptosis is really programmed. Cell death and apoptosis can actually be a good thing. Um, even though it may seem like a bad thing cells dying, a apoptosis cell death would be triggered if too many errors accumulate. And so by the cell undergoing apoptosis, or cell death, it's actually preventing the accumulation of errors. And so apoptosis once again can be a good thing. Under the right scenario, And so really, it's actually a cell that ignores these cell cycle checkpoints that can actually lead to problems more specifically, lead to the development of cancer. And so later, in our course, we're also going to talk Maura Maura about cancer as well. And so, as we move forward in our course and talk Maura about thes cell cycle checkpoints, it's important for you to keep in mind that these cell cycle checkpoints are very important for regulating the cell cycle to ensure that cancer does not develop. And so this here concludes our introduction to cell cycle regulation, and as we move forward in our course, we'll talk about these cell cycle checkpoints, so I'll see you all in our next video.