Consistently, cytochrome c was released from mitochondria to the cytoplasm, and cleavage of caspase 3 and poly ADP-ribose polymerase 1 (PARP1) increased in NPTX1-overexpressing cells, indicating that NPTX1 promotes mitochondria-related apoptosis in HCC cells. The gene discussed is CYCS; the disease is hepatocellular carcinoma.