So these natural killer cells circulate inside our blood and they respond to these cytokines released by the math cell and other cells and they move into that infected area from the blood into the tissue. So these natural killer cells circulates in the blood and moves into effective tissue. They bind onto cancer cells or infected cells and once they bind they release powerful digestive enzymes that drill holes in that infected cell or cancer cell and that lysis our cell. Now, once the cell lyses we have these macrophages that are also called upon by these cytokines released into our blood as a result of that mast cell and other cells. Now, these macrophages are the largest type of phagocytic cell in our body. They basically move from the blood into our tissue and they begin engulfing anything that is harmful or pathogenic to the healthy cells of our body.