In plasma, levels of NFL were higher in neurosarcoidosis patients median 28.2 pg/mL (IQR 11.5–49.3) compared to 6.2 pg/mL (IQR 4.3–8.2) in extra-neurologic sarcoidosis patients and 7.1 pg/mL (IQR 6.2–9.0) in healthy controls (p = 0.0001). Here, NEFL is linked to sarcoidosis.