Selective induction of apoptosis in TEVp-overexpressing HEK293T cells by ENLYFQ-GrB. HEK293T cells were transiently transfected to co-express either mCherry or TEVp (each tagged with mCherry) plus (a) wild-type GrB, (b) ENLYFQ-GrB, or (c) GrB S183A. Co-expression of ENLYFQ-GrB and TEVp resulted in the appearance of a small, but significant, population of cells exhibiting decreased FSC, signifying the specific induction of GrB-mediated cytotoxicity. Contour plots show the SSC vs. FSC scatter of transfected (mCherry+) and DRAQ7– cell populations. Plots shown are representative of triplicate samples.