The group of Prof.Thurnher performs tumor immunotherapy research since many years. The clinical trials with dendritic cells in patients with renal cell carcinoma, which were initiated in 1997, have been a première in Austria and have also been among the first world wide. Dendritic cells, which are the sentinels of the immune system, are leukocytes like all immune cells. They pick up antigens from pathogens or tumor cells and present them to T cells, which are thus enabled to recognize pathogens or tumor cells in a cognate fashion. Dendritic cells translate danger signals into an antigen-specific immune response. Dendritic cell-based tumor immunotherapy activates T cells and redirects them to attack tumors and tumor metastases.