To form hypotheses about the association of different NfL species with neurodegeneration, we performed Spearman’s correlation analysis between each of the six quantified NfL peptides and additional previously measured biomarkers and clinical measures: general markers of clinical dementia (CDR-SB, MMSE), biomarkers of amyloid plaques (PET PiB, CSF Aβ 42/Aβ 40)18 and tau biomarkers (CSF t-tau, CSF phospho-tau immunoassay and mass spectrometry measures of CSF ptau 181, 205 and 217 occupancy),15,20Supplementary Fig. 6 and Supplementary Table 4. Here, MAPT is linked to dementia.