Show description/summary:1) Serum neurofilament light chain as a biomarker for mild traumatic brain injury in contact sports2) What's Trending: Biomarker validation and precision medicine in Parkinson disease.This podcast begins and closes with Dr. Robert Gross, Editor-in-Chief, briefly discussing highlighted articles from the May 9, 2017 issue of Neurology. In the first segment, Dr. Kristen Heinan talks with Dr. Pashtun Shahim about his paper on serum neurofilament light chain as a biomarker for mild traumatic brain injury in contact sports. In the next part of the podcast Dr. Alberto Espay focuses his discussion with Dr. David Standaert on biomarker validation and precision medicine in Parkinson disease. Disclosures can be found at Neurology.org.DISCLOSURES: Dr. Espay serves as Associate Editor for the Journal of Clinical Movement Disorders; serves as an editorial board member of Parkinsonism and Related Disorders and The European Neurological Journal; serves on the scientific advisory board for Solvay Pharmaceuticals, Inc. (now Abbvie), Chelsea Therapeutics International, Ltd., Teva Pharmaceutical Industries Ltd., Impax, Merz Pharmaceuticals, Inc., Pfizer Inc, Solstice Neurosciences, Eli Lilly and Company, ACADIA Pharmaceuticals, Inc. and USWorldMeds; is a consultant for Chelsea Therapeutics International, Ltd., Solvay Pharmaceuticals, Inc. (now Abbvie), ACADIA Pharmaceuticals, Inc., Cynapsus and Lundbeck, Inc; receives royalties for publications of books from Lippincott, Williams & Wilkins and Cambridge University Press; serves on the speakers' bureau of UCB, Teva Pharmaceutical Industries Ltd., American Academy of Neurology and Movement Disorders Society; receives research support from the CleveMed/Great Lake Neurotechnilogies, Michael J. Fox Foundation and the NIH.Dr. Standaert serves on scientific advisory boards for the American Parkinson Disease Association; serves on the DSMB for Shire/Biropharma; received honoraria from the Movement Disorder Society and Georgia Regents University; is Associate Editor for Movement Disorders; receives publishing royalties for Movement Disorders (McGraw-Hill Publishers, 3rd ed.); consulted for Serina Therapeutics, Kirchner Group, Teva Neuroscience, Abbvie, and the U.S. Attorney's Office; receives research support from Abbvie, Acerta Pharmaceuticals, Ceregene, Quintiles, NIH, Alabama Department of Commerce, American Parkinson Disease Association, Michael J. Fox Foundation for Parkinson Research, Bachmann-Strauss Dystonia & Parkinson Foundation, and the Dystonia Medical Research Foundation.All other participants report no disclosures.