Only CSF-NFL showed an acceptable diagnostic performance; we found that CSF-NFL levels at a cut-off of 969 pg/mL could differentiate the patients with encephalitis associated with tumors from those without tumors and the controls, with an area under the ROC curve of 0.93, excellent sensitivity (100%) and moderate specificity (76%) (Figure 1E,F). This evidence concerns the gene NEFL and encephalitis.