Figure 5.

Partial tumor growth inhibition in IL-1 but not non-IL-1 producing xenografts treated with systemic IL-1ra protein. Two times 10⁶ tumor cells were injected s.c. into the flanks of athymic nude mice. On the day of tumor injection, s.c. IL-1ra therapy at various doses or placebo began and was administered daily into the opposite flank from tumor injection. IL-1ra consistently resulted in a statistically significant decrease in growth rate of all three IL-1-producing tumors tested but had no effect on two non-IL-1-producing tumors.