Scientists have identified new processes that form protein “clumps” that are characteristic of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). How these proteins, which can bind RNA in normal cells, stick together has remained elusive until recently, when scientists demonstrated that they demix from the watery substance inside cells, much like oil separates from water. The team sheds light onto the molecular interactions behind the process in patients with defects in the C9orf72 gene.