The prognosis of the patients with PCR-positive cancer was significantly poorer than those with PCR-negative cancer in the T3 (P<0.0001; Figure 3A) and T4 (P=0.048; Figure 3B) subgroups, while no significant difference in prognosis was found between the CEA and/or CK20 expression in the T1 and T2 subgroups (data not shown). The gene discussed is CEACAM5; the disease is cancer.