Mitochondria and pathogen immunity: from killer to firestarter

Serving as an innate defence mechanism, invading pathogens elicit a broad inflammatory response in cells. In this issue, Brokatzky et al (2019) report that pathogens can cause activation of BAX/BAK which permeabilises a limited number of mitochondria. Induction of DNA damage, or release of mtDNA, triggers STING‐dependent pro‐inflammatory cytokine expression and secretion, revealing an unexpected role for the mitochondrial apoptotic machinery in immune defence.