Neurofilament light chain (NfL) protein, as a part of the cytoskeletal structure of neurons, is widely accepted as a neuroaxonal injury marker in the cerebrospinal fluid (CSF) and blood in various neurodegenerative diseases [12], with higher blood levels in relation to clinical outcomes after mild and severe TBI [13,14]. The gene discussed is NEFL; the disease is neurodegenerative disease.