GRN and frontotemporal dementia: Beyond TNF-α, previous studies on blood-based inflammation biomarkers in FTLD reported an increase of plasma IL-6 levels in 230 patients with FTD, irrespective of the clinical and genetic disease subtype,55 in addition to increased serum levels of IL-6 in 14 carriers of GRN mutations.56 Studies on serum/plasma levels of M-CSF, IL-17A, IL-12 and IP-10 in patients with FTLD are limited or inconclusive.