Systems Biology is a modern field of biology. It concerns interactions rather than constituents, although knowing the constituents of the system under study may be a prerequisite for success. With the advent of modern “-omics” techniques, a huge amount of data is becoming available. To analyze these data is one of the goals of Systems Biology. Moreover, it is devoted to studying the emerging properties that arise due to complex interactions. Systems Biology combines theory with experiment in iterative cycles: Models are derived from experimental data and are then continuously validated and refined. The models, in turn, serve for the planning of new experiments. Systems Biology is becoming more and more relevant in age research because aging is a complex, systemic phenomenon.