We make a simple model for how cancer and immune cells behave in order to explain the structures seen in microscopic images of the tumor micro environment that have been obtained both from mice. The large structures are emergent from microscopic rules, which makes the simulation challenging since many scales are involved. We try our best to estimate what parameter values are useful, but ultimately need to experiment a lot with different setups to find what fits experiments best. This testing is time consuming so we would like to be able to run many tests in parallel. Each simulation also benefits from running on many cpus (scipy fft parallelizes well), and needs 300-1000 GB of memory.