CASP9 and hepatocellular carcinoma: To determine whether NFATc1 induces HCC cell apoptosis by activating the extrinsic apoptosis pathway, we examined apoptosis signaling caspase proteins (caspase 8, caspase 3, and caspase 9) by Western blot and found that ectopic expression of NFATc1 elevated expression of the active form of caspase 8 and caspase 3, but not caspase 9 (Figure 4B and S4), indicating NFATc1 induces HCC cell apoptosis by activating the FasL‐mediated extrinsic signaling pathway.