There are precedents for such dual roles; for example, some dual-specificity phosphatases (DUSP family) can either suppress or promote cancer depending on context 41, protein misfolding can have gain- or loss-of-function consequences in neurodegenerative diseases 42, and certain microbial pathogen effector proteins can both facilitate infection and trigger plant immune resistance 43. Here, DUSP5 is linked to neurodegenerative disease.