C9orf72 and amyotrophic lateral sclerosis: Prior work had shown increased LAMP-1 and CD68 immunoreactivity in ALS cases with C9orf72 repeat expansions [63, 64], however C9orf72-/- motor neurons and those from ALS-C9orf72 cases have fewer lysosomes, despite higher LAMP-2 content in lysosomal membranes [23].