SIGMAR1 and amyotrophic lateral sclerosis: Interestingly, RNA-Seq results also found that expression levels were changed for two familial ALS-related genes, TARDBP and SIGMAR1. To further expand on our results from RNA-Seq and RT-qPCR that TARDBP expression levels were increased, we stained C9-ALS skeletal myocytes for full-length TDP-43 and phosphorylated TDP-43.