CDKN1A and colonic neoplasm: According to the gene expression analysis profiles of c-Myc and p21 in a cohort of cancer patients, including patients with the top five cancer types in the U.S., the c-Myc mRNA levels in the tumor tissues were increased to the highest level in colon cancer among these major cancer types while accompanying a decrease in p21 mRNA in comparison to normal control tissues (Figure 8).