NEFL and Parkinson disease: Regarding pure autonomic failure, subjects with this condition may phenoconvert to PD, DLB, or multiple systems atrophy (MSA) and there is some evidence that the kinetics of the aSyn-SAA curve (i.e., maximum fluorescence and time to positivity) and additional information from neurofilament light chain testing in CSF may offer prognostic information about which synucleinopathy a subject is likely to phenoconvert to [163, 165].