After applying random effect model for pooling of estimates, the pooled estimate of CSF tau in Alzheimer's disease studies was 414.073 pg/mL (CI: 237.170–590.975) while it was quiet low as 83.500 pg/mL (CI: 36.406–130.595) in dementia-due-to-other-causes studies. This evidence concerns the gene MAPT and dementia.