Effect of cell stress on VKOR KO cells. (A) Cell viability with regard to H₂O₂ treatment was assessed in WT (purple), VKORC1 KO (red), VKORC1L1 KO (blue), and DKO (green) HEK 293T. Curves showing normalized values for 3 replicates including error bars representing standard error of the mean. (B) Effect of K₁ and K₁>O treatment on cell viability. Negative control without H₂O₂; positive control with 75 µM H₂O₂. Cells were incubated with 75 µM H₂O₂ and K₁ or K₁>O (each 12 µM).