Interestingly, while neuronal presynaptic proteins such as SYN II degrade rapidly via the ubiquitin-proteasome pathway, a considerably more stable NF-L turns over much more slowly, and in neurological disease is accompanied by a pathological shift from an intracellular neuronal cytoplasmic location across multiple membrane barriers into various biofluid compartments [16,20,54]. Here, NEFL is linked to nervous system disorder.