 mutations in the gene encoding PC1 cause ADPKD, a common genetic renal disease. Here, the authors show that expression of the C-terminal 200 amino acids of the large PC1 protein in mouse models of ADPKD suppresses cystic disease through an interaction with the mitochondrial enzyme NNT. This article was authored by Laura Anuchik, Valeria Padavano, Georgia Schiena, and others.