PARP1 and neoplasm: Morphometric measurements of colon sections have shown that colon tumor tissue contained about three times greater amount of PARP-1 protein than unaffected colon tissue (mean 6.4, range 3.80–9.0 in tumor versus 2.4, range 1.0–4.0 in normal colon, p<0.00001, Fig. 3B).