Clinical investigations suggest that the cerebrospinal fluid (CSF) levels of HMGB1 in patients with subarachnoid hemorrhage (SAH) demonstrate a positive correlation with pro—inflammatory factors, such as IL—6 and TNF—α, and that the degree of HMGB1 elevation is closely related to the severity of the disease [353]. Here, HMGB1 is linked to subarachnoid hemorrhage.