NEFL and nervous system disorder: Both NfL and pNfH have been proved to be promising diagnostic biomarkers for ALS, although pNfH demonstrated a slightly higher performance than NfL in CSF in differentiating ALS from disease mimics or other neurological diseases, in terms of sensitivity and specificity (sensitivity: 78–100% pNfH vs. 85.4%–96.2% NfL; specificity: 68.8–88.0% pNfH vs. 53.5%–78.0% NfL), when measured with enzyme‐linked immunosorbent assay (ELISA).6, 27, 29