This protein family consist of CLN5 and CLN5-like proteins. Defects in CLN5 are the cause of neuronal ceroid lipofuscinosis type 5 (CLN5), also known as Finnish variant late-infantile neuronal ceroid lipofuscinosis (vLINCL). Neuronal ceroid lipofuscinoses are progressive neurodegenerative, lysosomal storage diseases characterised by intracellular accumulation of autofluorescent liposomal material [, , , , , , , ].