Involved in microtubule-dependent, anterograde transport of late endosomes and lysosomes. Defects in CLN3 are the cause of neuronal ceroid lipofuscinosis type 3 (CLN3); also known as Batten disease. A form of neuronal ceroid lipofuscinosis. Neuronal ceroid lipofuscinoses are progressive neurodegenerative, lysosomal storage diseases characterized by intracellular accumulation of autofluorescent liposomal material, and clinically by seizures, dementia, visual loss, and/or cerebral atrophy. The hallmark of CLN3 is the ultrastructural pattern of lipopigment with a fingerprint profile, which can have 3 different appearances: pure within a lysosomal residual body; in conjunction with curvilinear or rectilinear profiles; and as a small component within large membrane-bound lysosomal vacuoles. The combination of fingerprint profiles within lysosomal vacuoles is a regular feature of blood lymphocytes from patients with CLN3. Belongs to the battenin family. 5 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.