The present invention provides means to affect the dynamics of actomyosin network in natural killer (NK) cells, and thereby to confer selective control on killing efficiencies of NK cell populations. Compositions and methods of the present invention, particularly those using small molecules, provide a powerful tool for controlling NK cell activation and function in various conditions, in health and disease, most notably in viral infections, autoimmunity, immunodeficiency, GVHD and cancer.
