In light of these arguments, it is tempting to speculate that both secondary accumulation of TDP-43 and primary TDP-43 pathology may occur in AD cases: Secondary accumulation of pTDP43409/410 and pTDP-43409-positive material in ADTDP + CTF cases and primary development of TDP-43 aggregates in ADTDP + FL cases. The gene discussed is TARDBP; the disease is Alzheimer disease.