Methods: This is a single arm open-label study. Each patients will receive four cycles of subcutaneous Proleukin (Interleukin-2, IL-2) (Week-1; 1.5 million IU (MIU)/d from Day-1 to Day-5, Week-3, -6, -9; 3MIU/d from Day-1 to Day-5) in the hospital. The patients will be followed up for 3 months (Week-21).