GFAP and brain injury: GFAP was believed to occur in non-myelinating Schwann cells in the peripheral nervous system (PNS), and the enteric glial cells in the enteric nervous system (ENS) (Laranjeira et al., 2011; Gulbransen and Sharkey, 2012), which might be a suitable measure for patients with brain injury (Schiff et al., 2012).