And that's because this dendritic cell brought a specific type of antigen to this cytotoxic T cell. So it will only react to this specific antigen that was brought to it. Now, finally, we also have suppressor T cells and memory T cells. Memory T cells are like memory B cells. They essentially help us with reinfection. They keep a copy of our antibody while suppressor T cells help us regulate the different types of white blood cells in our body and they use a negative feedback mechanism to tone down or turn down our immune response.