In a study of 15 head trauma patients, cleaved tau protein levels in cerebrospinal fluid (CFS) were more than 1000 times higher than neurologic or non-neurologic (psychiatric) controls (1519 ± 3019 vs. 0.03 ± 0.1 or 0 ± 0 ng/mL, respectively) [25]. The gene discussed is MAPT; the disease is myalgic encephalomeyelitis/chronic fatigue syndrome.