A stimulation system includes an energy source, an electronics unit with a controller, and an actuator that is coupled with the electronics unit and/or the energy source. The actuator emits electromagnetic waves for stimulation of genetically manipulated tissue. The electronics unit is disposed in a housing. The stimulation system is configured for at least temporary implantation in a human or animal body. The controller controls the stimulation of tissue in the body by way of the electromagnetic waves emitted by the actuator. A selector of the stimulation system selects the area of the said tissue for stimulation. The selector includes a masking device for masking certain areas of the tissue, so that an intensity of the stimulation for the masked areas is reduced or equal to zero.