MAPT and early-onset autosomal dominant Alzheimer disease: Our findings that p-tau181 levels are associated with whole-brain 18F-AV-1451 load extend findings to the early PD context that have been made similarly in LBD with the tau-PET ligand 18F-RO948 and plasma p-tau181,54 and using CSF p-tau181 and the ligand 18F-MK6240 in a bigger cohort of healthy participants and individuals on the Alzheimer’s disease spectrum.55