Decrypting pathogen effector networks Many disease-causing bacteria use a molecular syringe to inject dozens of their proteins, called effectors, into intestinal cells, blocking key immune responses. Ruano-Gallego et al. used the mouse pathogen Citrobacter rodentium to model effector function in vivo. They found that effectors work together as a network, allowing the microbe great flexibility in maintaining pathogenicity. An artificial intelligence platform correctly predicted colonization outcomes of alternative networks from the in vivo data. However, the host was able to bypass the obstacles erected by different effector networks and activate complementary immune responses that cleared the pathogen and induced protective immunity. Science , this issue p. eabc9531