As shown in Figures 4, 5 and Table 3, the levels of blood NfL were distinctly increased in PSP and MSA patients compared to HC (PSP, P < 0.001; MSA, P < 0.001) and patients with PD (PSP, P = 0.024; MSA, P < 0.001). The gene discussed is NEFL; the disease is multiple system atrophy.