This thesis summarizes findings with a novel therapeutic approach to neuroblastoma, combining gene therapy using the chemokine fractalkine (FKN) with targeted IL-2 (ch14.18-IL-2). Own contributions to this topic are documented by four publications provided in the appendix. They are listed under ‘Own publications’ and are referred to in the text using square brackets ([]). These findings were supplemented with yet unpublished results summarized in 12 figures reporting novel findings with this concept. Publications of other authors are cited in numerical order in round brackets (()).