Despite differing in disease frequency and clinical course, ALS and SBMA possess key overlapping features that are associated with dysfunctions of cell-clearing systems, namely protein aggregation due to expanded C9ORF72 or AR within both motor neurons and skeletal muscles, as well as early neuromuscular junction (NMJ) and axonal alterations [10,15,16,17,18,19,20,21]. The gene discussed is AR; the disease is Kennedy disease.