After controlling potential confounders including age and sex, the plasma total tau level was not significantly different between groups (controls: 1.13 ± 0.66 pg/mL; PD: 2.00 ± 1.11 pg/mL; CBS: 1.66 ± 0.75 pg/mL; PSP: 1.99 ± 0.65 pg/mL; FTD: 1.78 ± 0.84 pg/mL; AD: 2.63 ± 0.47 pg/mL; by ANCOVA adjusted for age and sex), although the level was numerically higher in the AD dementia group. The gene discussed is MAPT; the disease is Alzheimer disease.