Studies that focus on traumatic brain injury patients do not show any correlation between a disrupted BBB, using QA, and the peak serum levels of S100B (Bellander et al., 2011), or by using a ratio of the CSF and serum S100B compared to QA (Kleindienst et al., 2010), hence indicating better correlation between actual injury and S100B levels and not the degree of BBB disruption. Here, S100B is linked to brain injury.