ACTR1B (actin related protein 1B) is a component of the dynactin complex involved in microtubule-based vesicle motility and centrosomal localization 1. It functions as a structural constituent of the cytoskeleton and associates with membrane compartments including secretory granules and extracellular exosomes. Mechanistically, ACTR1B participates in cellular motor protein complexes essential for retrograde axonal transport and vesicular trafficking. Genetic variants in ACTR1B show epistatic interactions with dopamine signaling genes (DRD2, DRD3) in substance use disorders, demonstrating sex-dependent effects more pronounced in males 2. The protein's cis-regulated abundance in brain tissue is causally associated with smoking initiation risk 3 and bitter-sweet taste perception 4. Disease relevance extends across multiple neuropsychiatric and neurodegenerative conditions. ACTR1B expression changes were identified in Parkinson's disease substantia nigra and blood samples 5, and anti-ACTR1B antibody levels predict antipsychotic treatment remission trajectories in first-episode schizophrenia 6. Animal models reveal ACTR1B knockdown reduces locomotion following ethanol exposure, implicating it in alcohol-related behaviors 7. Clinically, ACTR1B represents a potential therapeutic target for substance use disorders and neuropsychiatric conditions, though its role in hereditary peripheral neuropathies remains limited 1. Further functional characterization is needed to establish clinical utility as a diagnostic or therapeutic target.