Sophie Meyer examines the history of tumor immunology in the GDR as an example of scientific research in the former Eastern Bloc during the Cold War. The focus of the study, which centers on the 1960s and 1970s, is the research site in Berlin-Buch, where efforts were made early on to combine basic research and clinical research under one roof. Using the example of an immunological test for cancer diagnosis, the MEM test, which was politically promoted in the 1970s, the scientific community of immunologists in the GDR and the behavior of individual actors under political pressure are also analyzed. This raises the question of the extent to which, alongside the authoritarian structure of the GDR, characteristics of a "small state" played a role.