IL17A and nervous system disorder: Despite the body of literature on IL-17 impacting outcome in other neurological diseases, there have been only limited investigations on the role of IL-17 on outcome from TBI.16 In a murine model of TBI, Th17 polarization driven by M1-like macrophages peaked in the brain and blood at 24 h after injury and persisted significantly above sham levels out to 3 weeks from injury.12,16 In a study of pharmacological inhibition of the IL-17 axis in a TBI model, Li and colleagues reported reduced neuronal apoptosis and attenuated neurological deficits.17