In a previous study, Tsai and Chen [6] prepared a highly stable catechin nanoemulsion from green tea leaf waste and reported that it was effective in inhibiting the growth of prostate cancer cells PC-3 with the IC50 being 8.5 μg/mL through activation of caspase-8, caspase-9 and caspase-3. Here, CASP9 is linked to prostate cancer.