Don’t Bite the Hand that Feeds You

Eukaryotic-bacterial symbioses are ubiquitous in nature. Pathogens and symbionts employ similar machinery, yet symbionts can minimize host damage. In this issue of Cell Host & Microbe , Enomoto et al. (2017) demonstrate how quorum sensing regulates expression of virulence genes at appropriate times, thereby enabling symbiont retention throughout the host lifespan.