Researchers at the Perelman School of Medicine at the University of Pennsylvania have identified a brain immune protein that may play a major role in the progression of Parkinson's disease (PD). Their findings, published in Neuron , suggest that blocking this protein with monoclonal antibodies could eventually lead to treatments that slow the disease in its earliest stages. The protein, known as glycoprotein nonmetastatic melanoma B (GPNMB), appears to help harmful Parkinson's-related damage spread from one brain cell to another. Scientists say targeting it may offer a new strategy for slowing the worsening of the disease over time. "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.…