We devised an in vitro assay to verify the interaction between TDP-43 LCD fibrils and recombinant PrPC and subsequently tested TDP-43 fibril toxicity in two different cell lines, human SH-SY5Y and mouse neuroblastoma (N2a) cells, engineered to express low or high levels of PrPC. The gene discussed is TARDBP; the disease is neuroblastoma.