The authors investigated @ functionally significant polymorphisms in @ genes ( methylenetetrahydrofolate reductase -LSB- MTHFR -RSB- -LSB- C@T , A@C -RSB- , SLC@A@ -LSB- G@A -RSB- , SHMT@ -LSB- C@T -RSB- , dihydrofolate reductase -LSB- DHFR -RSB- -LSB- Del@bp -RSB- , TS @del , and TSER ) involved in folate metabolism in @ patients with TNM stage II or III rectal cancer enrolled in a phase @ adjuvant clinical trial of @ regimens of @-FU and radiotherapy ( INT-@ and SWOG @ ) .