FABP4 and brain disorder: The four candidates, GFAP [30–34], NEFL [35, 36], MMP3 [37–39] and FABP4 [40–43] have previously been associated with brain tumors in small studies and have also been shown to be elevated in plasma and cerebrospinal fluid (CSF) of patients with other brain disorders, including traumatic brain injury, neurodegeneration, multiple sclerosis, etc [44–48].