To computationally determine whether targeting PIAS1 would predict changes in the HD mitochondrial proteome, we first compared the changes in the mitochondrial proteome of HD iPSC-neurons (Q109 vs Q18) described above with findings from our prior study36 of gene expression in the same type of differentiated neurons following PIAS1 knockdown (Supplementary Fig. 5a, b). Here, PIAS1 is linked to Huntington disease.