The immune system is under constant pressure from pathogens to evolve and mount a sufficiently strong response. At the same time, an over-responsive immune system can lead to tissue damage and autoimmunity. How these conflicting demands have shaped human immunity is not well understood.
Here, we focus on the innate immune response – a cell-intrinsic expression program that acts as the first line of defence against pathogens. We characterise this program’s transcriptional divergence between species and