After a variety of phase I clinical studies indicating clinical safety and effectiveness without significant toxicity, either after single or repeated ch14.18 antibody administration (175, 176), a phase II clinical trial showed that the use of ch14.18 combined with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-2 (IL2) compared to the ch14.18 alone in metastatic neuroblastoma patients was associated with a significantly improved outcome as compared with standard therapy in patients with high-risk neuroblastoma (177). Here, IL2 is linked to neuroblastoma.