Protein aggregates have a bad reputation in conditions such as Alzheimer’s disease and Parkinson’s disease, but in bacteria, inheritance of aggregates by daughter cells may help protect against the same toxic stresses that triggered them in parental cells, according to a new study publishing 28 August in the open access journal PLOS Biology, by Sander Govers, Abram Aertsen, and colleagues at KU Leuven, Belgium. The aggregates thus serve as a kind of inherited memory, protecting offspring against the challenges experienced by their ancestors.