GFAP and brain injury: Data analysis was performed from May 26, 2023, to March 27, 2024.<h4>Exposure</h4>Sport-related concussion, defined as at least 1 observable sign and/or 2 or more symptoms.<h4>Main outcomes and measures</h4>Primary outcomes were serum GFAP and NfL levels at 24 hours, and 1, 2, 4, 6, 8, 12, and 26 weeks.