To examine whether cancer cells are responsible for the high expression of pro-apoptotic markers in hepatocytes, we assessed the expression of proapoptotic markers (cleaved caspase-3 and cleaved PARP-1) in immortalized human hepatocytes (IHH) upon their indirect contact with colorectal cancer (LS174, SW620 or HT29) cells using the insert coculturing approach (Figure 2a). This evidence concerns the gene PARP1 and cancer.