Further supporting a role for DNA methylation in ALS is the fact that DNA-(cytosine-5)-methyltransferase 3A (DNMT3A) was shown to be overexpressed in the brain and spinal cord of ALS patients, and this overexpression seems to be related to cell death in motor neuron like cells in vitro (Chestnut et al., 2011). Here, DNMT3A is linked to amyotrophic lateral sclerosis.