MAPT and Alzheimer disease: We previously reported that CSF sPDGFRβ level was elevated and correlated with CSF t-tau and p-tau levels in clinical AD patients confirmed by CSF biomarker status (i.e., t-tau > 400 pg/mL, p-tau > 60 pg/mL and Aβ42 < 550 pg/mL) [4].