(A) Renca tumor was implanted in the livers of Balb/c mice intrasplenically. Three days after tumor implantation, mice were treated with vehicle control (VC), IL-18, IL-12 or IL-18/IL-12 for three weekly cycles. On day 14, livers were harvested and tumor nodules were counted. (B) Wildtype Balb/c Mice were treated with normal rabbit serum (NRS) or anti-asGM1 to deplete NK cells concurrent with intrasplenic implantation of Renca tumors. (C) CD1d −/− mice deficient in NKT cells were inoculated intrasplenically with Renca. Three days after tumor implantation, mice received daily i.p. administration of vehicle control (VC), IL-12, IL-18 or IL-18/IL-12. On day 17 after tumor implantation, livers were harvested and the number of tumor nodules was counted. Each treatment group consisted of 8-10 mice and results are representative of three experiments.