Before revision:   We provide a freely available Python implementation of the p-value method that may serve as a general tool for extracting the interaction rules in collective systems of self-driven agents.
After revision:  We therefore speculate that NK cells find wild-type tumor cells only by chance, but are programmed to leave a target quickly after a close encounter. We provide a freely available Python implementation of the p-value method that may serve as a general tool for extracting the interaction rules in collective systems of self-driven agents.