To have a better insight into the relationship between oxidatively damaged DNA/repair and PARP-1 and their involvement in cancer development, we presently investigated the mRNA/proteins expression of PARP-1 and OGG1 and the 8-oxodGuo level in DNA of normal and diseased colon tissues and in leukocytes of CRC patients and individuals developing benign adenomatous polyps as well as in leukocytes of control healthy subjects. The gene discussed is PARP1; the disease is cancer.