While our prior work demonstrated its neuroprotective function in AD by stabilizing reticulon 3 (RTN3) to suppress amyloid-β (Aβ) production [16], BAP31’s contribution to PD-specific mechanisms—such as dopaminergic neuron survival, α-synuclein aggregation, and mitochondrial dynamics—remains poorly characterized. Here, BCAP31 is linked to Parkinson disease.