Natural killer cell

Natural killer cells (NK) are a type 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 phagocytosis; 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.

See also:

• White blood cell