C9orf72 and amyotrophic lateral sclerosis: Furthermore, CRISPR knockouts of chromatin modifiers, CREBBP, KMT2D and KDM6A decreased tau levels in SH-SY5Y cells and have also been shown to protect human cells from the C9ORF72 dipeptide-repeat-protein toxicity, that causes amyotrophic lateral sclerosis and frontotemporal dementia74.