TARDBP and proteostasis deficiencies: To determine whether TDP-43 regulation of SMC1A occurs in other neuronal cell types affected by TDP-43 proteinopathy, we similarly evaluated SMC1A APA and protein expression in DIV38 iPSC-derived motor neurons (iPSC-MNs) in which TDP-43 was knocked down for 10 days (Supplemental Figure 6B).