Because BDNF, IL-8, IL-11 and UCHL-1 response to mild head injury with concussion has not been widely studied so far, as it occurs mostly in cases of traumatic brain injury, the aim of the current study was to test whether the levels of the abovementioned proteins are changed in children with mild concussion without loss of consciousness (LOC) compared to children with severe concussion and LOC. This evidence concerns the gene BDNF and brain injury.