We found that the immunoreactivity of Arl8a and Arl8b, both specifically recognized by the anti-Arl8a/b antibody (Additional file 1: Table S1), is significantly increased in AD patient brains compared to age-matched controls (Fig. 6a, b), indicating that the abundance of these functionally and structurally closely related proteins is abnormally elevated in AD patient brains. Here, ARL8A is linked to Alzheimer disease.