PDCD4 and breast neoplasm: Inhibition of PKCε-Nanog signaling by downregulating PKCε with PKCε siRNA or silencing miR-21 with anti-miR-21 inhibitor results in PDCD4 up-regulation and causes IAP/MDR1 (P-gp) reduction, as well as apoptosis/cell death and chemosensitivity in breast tumor cells [39].