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). Here, PARP1 is linked to colorectal cancer.