When mitochondria become damaged, they avoid causing further problems by signaling cellular proteins to degrade them. In a paper publishing April 11, 2019, in the journal Developmental Cell, scientists in Norway report that they have discovered how the cells trigger this process, which is called mitophagy. In cells with broken mitochondria, two proteins—NIPSNAP 1 and NIPSNAP 2—accumulate on the mitochondrial surface, functioning as “eat me” signals, recruiting the cellular machinery that will destroy them.