IL2 and renal cell carcinoma: Based on preclinical data suggesting a synergism between IL-2 and 5-fluorouracil (5-FU) on one hand and IFNα and 5-FU on the other, added to the well-known synergism of the association of IL-2 and IFNα (Cameron et al, 1988), the combination of IL-2, IFNα and 5-FU has been investigated in renal cell carcinoma.