MAPT and frontotemporal dementia: Frontotemporal lobar degenerations are clinically more heterogeneous, with several well-recognized clinical phenotypes, including the behavioral variant (bvFTD), primary progressive aphasias (PPAs), corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP), and with two main pathological groups distinguished by the accumulation of TAR DNA-binding protein 43 (TDP43) or the microtubule-associated protein tau [2].