The team describes peptideins as small proteins produced from genome regions that standard annotation often overlooks—part of what researchers term the “dark proteome.” Lead researcher Sebastiaan van Heesch is quoted in the institute’s announcement describing the findings as a distinct expansion of the known protein catalogue.
According to the press release, experimental work indicated that some peptideins are required for cell survival, while others were associated with processes such as cell division, DNA repair, and immune recognition. Several were reported at the cell surface, which the authors note may be relevant for immunology and cancer research.
The institute states that associated data have been deposited in public databases for other groups to analyse. The authors frame the work as an early map of a larger set of microproteins still to be characterised in detail.
For methods, validation, and clinical implications, see the announcement Thousands of previously unknown proteins discovered (Princess Máxima Center).