TDP-43WT or TDP-43G294A proteins can transfer from cell to cell in NSC-34 cells. NSC‐34 transiently transfected with TDP-43WT-tdTomato or TDP-43G294A-tGFP were either mixed (indicated by black arrows in schematic diagram) at the end of the incubation (A), immediately following transfection (B). Alternatively, cells were co-transfected to express both fusion proteins (C). After incubation for either 24, 48 or 72 h live intact cells were analyzed by flow cytometry. (A-C) Representative 2 parameter, pseudo-color flow cytometry plots showing identification of cells expressing TDP-43WT-tdTomato or TDP-43G294A-tGFP and cells containing both from the 48 h timepoint. (D) Histogram showing double positive cells as a percentage of all cells containing a fluorescent protein. Results shown as mean percentage of cells ± SEM, n = 3 independent experiments. Significant differences indicated with p value represent unpaired T-test comparisons between treatments indicated by line.