It is worthy of note that the expression of OAZ1, OAZ2, and OAZ3 genes, which encode major regulators of ornithine decarboxylation to putrescine through inhibition of ODC catalytic activity, and the expression of AZIN1 gene, which is involved in inhibition of antizyme (OAZ) family, did not change in the majority of CRC samples compared with normal samples. This evidence concerns the gene ODC1 and colorectal carcinoma.