Finding, in yeast, that the level of PBP1 modifies TDP-43 toxicity led to the discoveries that alterations in PBP1’s human homolog, ATXN2 (ataxin-2), increase the human risk for ALS, and that lowering the level of ATXN2 reduces the toxicity of TDP-43 in mice [17,18,19,20]. The gene discussed is TARDBP; the disease is amyotrophic lateral sclerosis.