- Therapeutic effect of 1 M tegafur-0.4 M 5-chloro-2,4-dihydroxypyridine-1 M potassium oxonate (S-1) on liver metastasis of xenotransplanted human colon carcinoma. Konno, H., Tanaka, T., Baba, M., Kanai, T., Matsumoto, K., Kamiya, K., Nakamura, S. Jpn. J. Cancer Res. (1999)