In addition, our present results are supported by the findings that CYP2A6*4 reduces plasma 5-FU concentration and increases the area of under the concentration-time curve (AUC) and Cmax for tegafur in non-small cell lung cancer patients treated with S-1 alone or in combination with cisplatin (Kaida et al, 2008). This evidence concerns the gene CYP2A6 and non-small cell lung carcinoma.