In general, gamma-enolase serum levels are better indicators than its tissue expression (Table 1).80 Levels of gamma-enolase are elevated in sera from patients with various cancers, however, its appearance in extracellular fluids without any apparent cellular damage is not clear.1,88 After stroke, brain injury or cardiac arrest, gamma-enolase is released into the cerebrospinal fluid and eventually into the bloodstream due to damage or death of neuronal cells or impairment of the blood-brain barrier integrity. This evidence concerns the gene ENO2 and injury.