We found that Npy mRNA expression was significantly increased in primary cancer cells of the C57BL/6J syngeneic KPR172HC model relative to primary cancer cells of the KPfloxC model via Q-RT-PCR (Fig. 4Bi), suggesting that Npy is important for the maintenance of the highly metastatic phenotype of the KPR172HC cancer cells. This evidence concerns the gene NPY and cancer.