Under both RT and refrigerated centrifugations, the levels of NFL in PD patients (RT: 16.47 ± 9.96 pg/ml; 4°C: 13.92 ± 8.31 pg/ml) were significantly higher compared with HCs (RT: 11.24 ± 4.06 pg/ml, P = 0.006, Figure 4C; 4°C: 9.84 ± 4.81 pg/ml, P = 0.017, Figure 4D). Here, NEFL is linked to Parkinson disease.