GRN and neurodegenerative disease: Similar to other neurodegenerative diseases, frontotemporal dementia (FTD) may have familial forms, which are associated with mutations in the genes coding for progranulin (GRN), chromosome 9 open reading frame 72 (C9orf72), or microtubule-associated protein tau (MAPT) (Lashley et al., 2015).