And this is a good thing because sometimes the cancer cells or infected cells lose the ability to create the MHC class One or the MHC class two complex. And that means it no longer contains these complexes on their membrane. And that makes it virtually invisible to all the cells of our body, all the white blood cells that require the MHC class One or class Two to actually detect those cells. So the special thing about these natural killer cells is that they can bind and destroy these cancer cells regardless of whether or not they have the MHC complex on the membrane. So once again, natural killer cells are lymphocytes that are part of our innate immunity. Now, majority of the white blood cells of our immune system can only recognize an abnormal cell, such as a cancer cell if it contains an antigen that is bound onto the MHC, the major histocompatibility complex membrane protein.