There are many drugs and therapies for Parkinson’s, but none halt progression of the disease. This is partly because we still do not understand exactly what causes Parkinson’s, so it is hard to figure out how to prevent it or slow it down. One potential target for new therapies is alpha-synuclein, a protein found in the human brain that is associated with the development of PD. Scientists are looking at ways to clear abnormal forms of alpha-synuclein from the brain using various immune therapies. Dr. Mark Guttman discusses these approaches based on what is known and unknown about Parkinson’s today.