Here, we investigated the amino acid code that determinescytotoxicityof the aging condensates using deep-sequencing data of >20,000mutantsof the TAR binding protein 43 (TDP-43).19 The presence of neuronal aggregates of mutant TDP-43 is a molecularhallmark of ALS.17,25,26 The cytotoxicity of TDP-43 mutants measured in yeast indicated thatmutations that enhanced amyloid formation decreased cytotoxicity,19 while mutations that affected the secondarystructure increased cytotoxicity. Here, TARDBP is linked to amyotrophic lateral sclerosis.