So during the middle stage, the HIV continually but slowly begins to kill off these helper T cells. And the final stage, the late stage, this is when we actually are diagnosed with Acquired Immune Deficiency Syndrome. This is when our HIV begins to kill off the helper T cells at a very high rate and the population of helper T cells drops to very low amount. And what that means is this is when our innate and acquired immune systems are weakened to the point where if any infection takes place, such as the common cold, flu, pneumonia, we essentially will die because of our body's inability to create to mount some type of defensive response. And this is when the person can also develop cancer. And that's because our immune system loses its ability to fight off cancer.