cells switch ribosomal genes – that lead to the production of a cellular protein factory called a ribosome – on or off. Ribosomal genes are either located in loosely packaged chromosomal regions that allow genes to be switched on or in tightly packaged chromosomal regions where genes are silenced. The ratio between active and silent ribosomal genes is important for cells, and disrupting ribosomal gene silencing is implicated in ageing and inherited human diseases. Ingrid has identified a protein complex called NoRC, which silences ribosomal genes by packaging them up more tightly.