FUS and amyotrophic lateral sclerosis: To test this hypothesis, we made EGFP-FUS constructs with the ALS-associated mutations R521G, R522G and ΔE15 (deletion of last 12 amino acids in the C-terminus), which respectively correlates with minor, moderate, and severe cytoplasmic accumulation of FUS, as reported by others both in ALS patients and in cell culture systems [6], [8], [9], [11].