Whereas human UNC13A does not normally include the cryptic exon, in the ALS and FTLD patients’ neurons, it has been found to be one of the genes with the most significant levels of alternative splicing, with the insertion of a 128 bp or 178 bp cryptic exon (Figure 4) between canonical exons 20 and 21, as a result of the loss of TDP-43 [125,133]. The gene discussed is TARDBP; the disease is amyotrophic lateral sclerosis.