In hereditary FTD with mutations in granulin (GRN) and the chromosome 9 open reading frame 72 (c9orf72), which play key roles in neuronal survival and RNA production and transport, symptomatic mutation carriers were observed to have significantly lower levels of NP2 compared to presymptomatic carriers and non-carriers [32]. Here, C9orf72 is linked to frontotemporal dementia.