The cytotoxic drug used, ganciclovir, is capable of destroying via apoptosis transduced cells and non-transduced cells from the cellular gap junction. This technique is known as the "bystander effect," which has suggested to scientists that the effect of some therapeutic agents may be enhanced by diffusion through gap junctional intercellular communication (GJIC) or cell coupling. GJIC is an important function in the maintaining of tissue homeostasis and it is a critical factor in balance of cells dying and surviving.