Natural killer cell: Meaning (information, definition, explanation, facts)

Natural killer cells (NK) are a type of lymphocyte (a white blood cell) and a component of nonspecific immune defense. These cells do not destroy the attacking microorganisms directly; they attack infected cells and cells that appear that they might cause cancer.

NK cells are not phagocytic; they weaken the target cell's plasma membrane, causing water and ions to diffuse into the cell and expanding it. Under this large pressure, the target cell lyses.