SNCA and multiple system atrophy: The data show that in the presence of 1 nM free P-α-synuclein monomer binding to plates coated with either α-synuclein (Fig. 11a) or P-α-synuclein (Fig. 11c) of approximately 35%–45% and 50–60% of the maximal binding is obtained for anti-P-α-synuclein NAbs in plasma from PD and MSA patients respectively.