The correlation of tau-associated microglial activation with GDS appeared to be driven by the AD cohort (4RT: rs = 0.354, p = 0.150; AD + AD-CBS: rs = 0.758, p = 0.029), whereas the correlation between tau-associated microglial activation and UPDRS appeared to be driven by the 4RT cohort (4RT: rs = 0.593, p = 0.007; AD + AD-CBS: rs = −0.698, p = 0.190). The gene discussed is MAPT; the disease is Alzheimer disease.