AR and amyotrophic lateral sclerosis: Similarly, the role of TDP-43 pathology remains inconsistent across SMA and SBMA models, while TDP-43 mislocalization is nearly universal in ALS [1,2], it is not a prominent hallmark in classical SMA, and in SBMA, mutant polyQ-expanded AR forms nuclear and cytoplasmic inclusions with distinct pathogenic cascades [4,206].