Intriguingly, PPT1, like CSPα, has been demonstrated to be associated with another NCL disease, ceroid lipofuscinosis neuronal 1 (CLN1), which is one of the two infantile forms of NCL and the most severe subtype of the disease (Cárcel-Trullols et al., 2015). This evidence concerns the gene PPT1 and infantile neuronal ceroid lipofuscinosis.