C9orf72 and amyotrophic lateral sclerosis: Previous studies by immunohistochemistry with two different anti-C9orf72 antibodies named sc-138763 and HPA023873 showed that C9orf72 is expressed chiefly in the cytoplasm of neurons, and is concentrated in the synaptic terminals in the brains of FTD/ALS with or without C9orf72 repeat expansion as well as those of controls.