Systems biology has become a new strategic tool in life sciences. General concepts of systems biology applied to immunology are summarized in the definition of systems immunology. This emerging field comprises highly promising strategies, including various -omics technologies, as well as mathematical modeling. These techniques allow us to gain insight into the dynamic behavior of the immune system. New knowledge about complex interactions of the numerous constituents of the immune system build the basis to find targets for immunotherapy. The aim of this seminar is to give a basic introduction to systems immunology.