A protein tied to the brain’s immune system may be helping Parkinson’s disease spread from cell to cell, and scientists believe stopping it could open a new path toward slowing the disease itself.

In a new study published in Neuron, researchers at the Perelman School of Medicine at the University of Pennsylvania reported that monoclonal antibodies were able to block the activity of a protein called glycoprotein nonmetastatic melanoma B (GPNMB), preventing the spread of harmful Parkinson’s-related protein clumps in laboratory experiments.

“Many patients with Parkinson’s disease are diagnosed in the early stages, when symptoms are relatively mild, but there is currently no treatment that slows the progression,” said lead author, Alice Chen‑Plotkin, MD, Parker Family Professor of Neurology. “These early results are a promising step towards developing this type of treatment.”