S-100 protein is a group of closely related small calcium-binding proteins (S-100a0, S-100a, and S-100b) and is found predominantly in brain cells[^2].
Neurosurgical Relevance
In patients after a Traumatic brain injury, serum levels of S-100 protein may be elevated[^3]. Serum levels of S-100 protein may also be elevated in patients with Creutzfeldt-Jakob disease[^1].