C9orf72 and behavioral variant of frontotemporal dementia: By mapping different neurotransmitter systems to cortical structure, we further confirmed that GABAergic signaling pathways contributed the most in predicting brain atrophy in individuals with C9orf72-bvFTD, which was also supported by findings that genes associated with GABAergic signaling are impacted in C9orf72-FTLD [36].