Supersulfides, many of which are produced by cysteinyl-tRNA synthetase (CARS), are essential compounds across many different lifeforms. However, the precise physiological roles of CARS-produced supersulfide are unclear. Now, using a strategically engineered yeast mutant with a deficient CARS gene, researchers from Japan have shown that supersulfides control cell longevity by mediating mitochondrial energy metabolism and regulating protein quality.