But this cancer cell loses the proper sequence of nucleotides to create the proper protein known as the MHC class One. And so we have none of these MHC class One proteins found on the membrane. And that is what triggers the natural killer cell to approach this cancer cell, bind to it, and begin releasing these granules that contain digestive enzymes. And these digestive enzymes poke holes inside the membrane of the cancer cell and that lysis and destroys the cell. And then a macrophage can swim by and pick up that remaining debris that essentially came from that lysed cell. Now, what about cytotoxic T cells, also known as killer T cells?