BDNF and concussion: Numerous genes and molecular factors, such as APOE (neuronal repair), BDNF (synaptic plasticity), IL-6, IL-10, TNFα (neuroinflammation), ENO2, UCHL1 (neuronal injury), GFAP, and S100B (glial activation, blood–brain barrier integrity), are implicated in mTBI [22,23,24,25,26,27].