MAPT and Alzheimer disease: Lastly, Tau5 is a control antibody that binds to a linear epitope of tau in the central proline-rich domain and provides EC50 of 0.093 + 0.043 nM for AD-tau, 0.138 + 0.125 nM for AD-P1 PFFs, and 0.103 + 0.065 nM for tau monomer.