IL1B and neoplasm: Because cetuximab in combination with rIL-1α showed some anti-tumor activity in athymic nude mice where NK cells (and not T cells) are present (Fig. 4A), and cetuximab along with IL-1 ligands have been previously reported to activate NK cell activity, we initially proposed that NK cells may be involved in the anti-tumor immune response to CTX + IL-1α-NP.