The purpose of this study is to determine whether interleukin-2 given 3 times weekly for 8 weeks in combination with rituximab is effective and safe when compared to rituximab given alone in the treatment of follicular NHL subjects that have never received rituximab as a treatment and are refractory or relapsed after previous chemotherapy.

Inclusion Criteria:

• CD20+ follicular B-cell non-hodgkin's lymphoma with at least 1 site of measurable disease.
• Previous treatment with 1 to 4 prior chemotherapy regimens
• ECOG performance status of greater than or equal to 2
• Life expectancy of greater than 18 weeks
• Meet safety lab requirements and organ function tests

Exclusion Criteria:

• Prior treatment with rituximab or IL-2
• Prior radioimmunotherapy including Zevalin or Bexxar
• 5 or more prior chemotherapy regimens
• Clinically significant cardiac disease, lung dysfunction, autoimmune disease, thyroid disease, active infection, unstable psychiatric condition, or HIV infection.
• History of allogenic bone marrow transplant
• Female subjects that are pregnant or breast feeding
• Immunosuppressive therapy including corticosteroids or investigational agents within 4 weeks prior to the planned start of study treatment