And these different proteins that end up on the membrane of these cancer cells can be read by certain white blood cells as being foreign antigens. And when these white blood cells locate these foreign antigens found on the cancer cells they can basically mark or label these cancer cells for destructions. So let's actually discuss what the different types of cells are in our immune system that basically are used to control and destroy these cancer cells. So even though the immune system as a whole functions to detect and destroy these cancer cells two particularly important types of white blood cells involved in the process of destroying infected and cancer cells are natural killer cells as well as cytotoxic T cells also known as killer T cells. And these are two different types of white blood cells. So let's begin with natural killer cells.