CASP3 and cancer: In epithelial cells, pEpi1 and pEpi2, MTCH2 knockdown (see Fig. 5) using shMTCH2-S1 did not significantly increase Caspase-3 activity (Fig. 6I) or nuclear TUNEL staining (Fig. 6J), again supporting a cancer cell-specific effect by MTCH2 knockdown.