To examine whether a clinicopathological association exists between the senescent tumor cells and CRC, we classified 130 CRC cases into 4 grades according to the proportion of p16INK4A (0: less than 1%; 1+: 1–20%; 2+: 20–40%; and 3+: more than 40% of cancer cells). The gene discussed is CDKN2A; the disease is colorectal carcinoma.