Figure 4A shows that the concentration of T-tau did not decrease significantly with consecutive transfer of CSF between tubes: there was a trend for a decline in measured T-Tau concentration in neat AD and control CSF (−93.8 pg/mL, CI: −194.9 to +7.3, P = 0.060, 5.1%; and −34.5 pg/mL, CI: −73.3 to +4.3 pg/mL, P = 0.066, 5.8% respectively), but no evidence for a decline with measured T-Tau concentration in AD and control CSF with Tween (14.2 pg/mL, CI: −94.7 to +123.1 pg/mL, P = 0.706, 0.4%; and −14.8 pg/mL, CI: −38.8 to +10.0 pg/mL, P = 0.157, 1.6% respectively). Here, MAPT is linked to Alzheimer disease.