MAPT and cerebral amyloid angiopathy: In contrast to our findings, increases in CSF PDGFRβ concentrations have been observed in AD defined clinically or by A/T/N classification.3,9,10,22,28 The lack of association between CSF PDGFRβ and Aβ status and Aβ or tau biomarkers was observed previously,3,5,9,10,22 although 1 study showed that Aβ burden modulated the association of PDGFRβ with tau-PET.29 Other authors also did not find an association between PDGFRβ and small vessel disease in cerebral amyloid angiopathy participants.9 The existing literature has important differences from our study that need to be considered.