Poly (ADP‐ribose) Polymerase (PARP) functions in gene regulation, DNA repair, and mitosis and meiosis regulation. ApcMin mice was created to have either wild type Parp1 (+/+) gene or carried a germ line knockout Parp1 (−/−) gene. Deficiency for Parp1 significantly enhanced tumorigenesis in ApcMin mice. The genes, Nf‐kappa B, Brac, Sox, Mappk, and Ctnnb, are known to be involved in DNA repair, inflammation and gene regulation, and Parp1 regulation in other tissues. We want to understand the potential mechanisms underlying Parp1's function as a tumor suppressor by measuring the changes in gene expression in Parp1 knockout (KO) colons.Colons from age and gender matched mouse pairs were used for RNA isolation. RNA was isolated using the Qiagen Rneasy Mini Kit. cDNA was created by reverse transcription (RT). Primers were designed using resources at NCBI and Primer Bank, and the specificity of PCR amplicons verified by polymerase chain reaction and gel electrophoresis. Quantitative real‐time PCR (qtRT‐PCR) was then performed to measure changes in gene expression in Parp1 KO colons compared with Parp1 wild type colons. Preliminary results indicate the loss of Parp1 modulates expression of Brca, Mappk, and Nf‐kappa B. Confirmation of these data is ongoing, along with analysis of additional candidate Parp1 target genes.