Remember, helper T cells are special type of T lymphocyte. Now, once the helper T cell comes to this area, it basically has this receptor on the membrane that can recognize this antigen that is bound to the MHC class two complex. And once it binds, it begins to release its own chemicals. Specifically, it releases into Lucan two. And what that chemical does is it moves on to B lymphocytes and T lymphocytes and it forces these two cells to essentially differentiate into their specialized form. So B lymphocytes produce memory B cells as well as plasma cells, while these T lymphocytes produce the memory T cells as well as our cytotoxic T cells.