Subsequent to our finding of GPNMB elevations in PD, it has also been discovered that GPNMB is elevated in the brain and CSF of patients with sporadic AD, and that GPNMB levels increase with disease progression in distinct AD transgenic mouse models and primarily colocalize with a distinct population of microglial cells located around amyloid plaques [182]. Here, GPNMB is linked to Parkinson disease.