CD44 and amyotrophic lateral sclerosis: Some of them deserve particular attention, given their critical role for motor neurons function: Gria4, that encodes a core subunit of the AMPA-type glutamate receptor, essential for excitatory synapses and that is affected during ALS progression; Adarb1, which encodes for the ADAR2 enzyme that edits glutamate receptor subunit B pre-mRNA by site-specific deamination of adenosines; Agrin, an heparan sulfate proteoglycan that is required for the development of postsynaptic specializations at the neuromuscular junction.