CASP9 and cancer: Compared with untreated tumor-bearing mice, those treated with Se/FO alone (TB-N group) expressed significantly lower mRNA levels of Ki-67, cyclin D1, and cyclin E (Figure 7a), markedly higher cleavage levels of apoptosis-related proteins caspase-3 and caspase-9, and non-significantly lower protein expressions of the cancer stem cell (CSC) markers CD24, CD29, and CD133 (Figure 7b,c).