MAPT and Alzheimer disease: (1) MCI criteria according Petersen et al. (1999), or compatible; (2) information about conversion to dementia (from controls or MCI); (3) information regarding the follow-up period; (4) baseline levels of T-tau and/or p-tau and/or Aβ42 for MCI that will progress to AD; (5) when two studies had overlapping samples, the one with biggest sample was chosen