Notably, neither denatonium benzoate nor quinine caused significant changes in TMRE fluorescence (measuring mitochondrial potential; Fig. S12A–E) or CellEvent reagent fluorescence (measuring caspase 3/7 activation; Fig. S12F–H) over the same time range that changes were observed with HNSCC cells. Here, CASP3 is linked to head and neck squamous cell carcinoma.