The currently available evidence shows that, while in the acute phase after stroke high blood levels of NfL seem to reliably reflect the extent of neuronal injury, in the late phase after stroke elevated NfL levels in the blood may serve as a biomarker of adaptive neural plasticity and a positive predictor of functional improvement and, therefore, also aid in predicting the effectiveness of neurorehabilitation. The gene discussed is NEFL; the disease is stroke disorder.