We used frontal cortex DNA methylation profiles from three FTLD datasets containing different subtypes of FTLD-TDP and FTLD-tau: FTLD1m (N = 23) containing FTLD-TDP C9orf72 mutation carriers and sporadic cases, FTLD2m (N = 48) containing FTLD-Tau MAPT mutation carriers, FTLD-TDP GRN and C9orf72 mutation carriers, and FTLD3m (N = 163) sporadic FTLD-Tau (progressive supranuclear palsy - PSP) cases, and corresponding controls. The gene discussed is C9orf72; the disease is Classical progressive supranuclear palsy.