PARP1 and colonic neoplasm: Cells having robust expression of MOAP-1 (HCT116 and HT-29 colon cancer cells) had robust cleavage of poly(ADP-ribose) polymerase (PARP) upon TNFα/CHX (extrinsic pathway) stimulation, whereas cells with reduced or absent endogenous MOAP-1 expression (MDA-MB-468, SKOV3 and H1299 cells) displayed very limited PARP cleavage upon TNFα/CHX stimulation (Fig. 6, A and B).