A recent study reported that PSP cases frequently show TDP-43 pathology in lower (38%) and upper (19%) motor neurons.30 Although in our collection we could not find a similar frequency (upper motor neuron: 6.7%; lower motor neuron: there were only a few neurites and positive glia), together with further studies describing involvement of lower motor neurons in PSP,11 these observations emphasize the vulnerability of the motor system in 4R tauopathies. Here, TARDBP is linked to supranuclear palsy, progressive, 1.