MBL2 and Parkinson disease: Additionally, since these structures are abundantly present at the synapsis, and synaptic disruption was recently reported in the PD substantia nigra through positron emission tomography (PET) imaging of synaptic vessel glycoprotein (33), one can hypothesize that these oligomannose residues-carrying proteins are incorrectly released to the extracellular space, that are recognized as foreign and binding to the MBL, which activates the complement system.