Now, T lymphocytes also are formed inside the bone marrow but T lymphocytes mature inside the thymus, which is basically a glam found in this region of our body. And what the Thiamis does is it basically checks, it tests these premature T lymphocytes and it ensures that the T lymphocytes don't actually attack our own cells of the body. And that's an important process because if the T lymphocytes do attack the cells of our body, what the thymus does is it ultimately Detroit these T lymphocytes. Now, one very important type of T lymphocyte that we spoke about earlier is the helper T cell. So once infection begins, some of these T lymphocytes differentiate into our helper T cells. Now, what exactly is the purpose of helper T cells?