Among 55 patients with colorectal cancers, DPD, OPRT, TS, TK, TP and dUTPase were positively expressed in 27% (15/55), 75% (41/55), 15% (8/55), 16% (9/55), 5% (3/55) and 40% (22/55) cases of primary tumours, respectively. The gene discussed is TYMS; the disease is neoplasm.