LAUSR

Description Investigating phase separation in neurodegeneration highlights evidence needed for causation How can a given gene, or gene product, or the cellular pathway it serves be determined as causal for neurodegenerative diseases instead of being a consequence of the underlying pathology? There are questions about the current theories that explain neurodegeneration, with therapeutic strategies producing disappointing results. On page 46 of this issue, Zhou et al. (1) attempt to address whether the aberrant phase separation of protein domains of low amino acid sequence complexity are causally pathogenic in several neurodegenerative diseases, including a form of frontotemporal dementia. Their approach has potential application in identifying causative factors in a range of disorders, as well as to the formation of membraneless organelles in normal cells.