1.2511 If any moderate adverse events occur at the 3 x 106 u/day level, the patients will be withdraw from the study; 1.252 In the presence of any severe adverse events (as listing in Appendix II), it requires immediate discontinuation of therapy; 1.2521 IFN-α will be discontinued until a return to baseline or moderate toxicity. Then IFN-α will be reinstituted at the dose level of 3 x 106 u/day; 1.2522 If moderate or severe adverse events occur at the 3 x 106 u/day level, the patients will be withdraw from the study.