MAPT and Alzheimer disease: Using an enzyme-linked immunosorbent assay to detect caspase-6-cleaved tau at Asp402 in postmortem CSF (using a polyclonal antibody), Ramcharitar et al. showed postmortem CSF levels mirror caspase-6-cleaved tau levels and active caspase-6 immunohistochemistry in the hippocampal sections of the same AD individuals and caspase-6-cleaved tau CSF levels correlate with AD severity and lower scores in neuropsychological tests [6].