Abnormal distribution of CD56 bright/dim natural killer cells 2017-09-04T12:15:25Z An abnormal distribution in the number of CD56 bright NK cells, as measured by flow cytometry. CD56, an adhesion molecule mediating homotypic adhesion, is used as a functional marker for NK cells. Abnormal distribution of CD56 bright/dim NK cells The cytotoxic activity of CD56 dim NK cells is significantly higher than that of CD56 bright cells (the CD56bright CD16 population being the less cytotoxic) and they contain much more perforin, granzymes and cytolytic granules. Abnormal natural killer subset distribution