To manipulate a computer circuit, you need to deliver time-dependent electrical signals to a specific location in the circuit. To guide the immune system into attacking cancer cells, my lab has been developing new technologies for timed local delivery of chemical signals. Spatial control is achieved by image guided delivery into tumor versus lymph node. Temporal control is achieved by programmable multi-drug release kinetics from the drug delivery implant. Different drugs can then be delivered into specific locations at specific times, to convince the immune system to attack cancer antigens.