GRN and frontotemporal dementia: Considering that progranulin knockout is a model of frontotemporal dementia, which is predominated in humans by behavioral abnormalities including compulsive eating and drinking, one may hypothesize that the observed phenotype is a manifestation of the frontotemporal neurodegeneration, possibly contributed by dysfunctions of hypothalamic neurons that show comparably high expression of progranulin [41].