Joachim (Jochen) Robert Kalden died on February 6, 2021 of complications after a coronavirus infection. Jochen was born on November 23, 1937 in Marburg/Lahn, one of four brothers and one sister to his father, a dentist, and his mother, a pharmacist. He went to school in Wetter, Marburg, and Frankenberg/Eder where he graduated. During his last years in high school, he visited the newly established art fair “Documenta” in Kassel, where he was confronted with modern art, which became one of his life-long fascinations. After his military service, he studied medicine in Freiburg im Breisgau, Marburg and Tübingen. In 1966, under the supervision of Walter Hartl, he obtained his Dr. med. (M.D.) in Tübingen. From 1967 to 1969, Jochen worked with James Irvine at the Department of Therapeutics, University of Edinburgh on the autoimmune disease myasthenia gravis, supported by a fellowship from the German Research Council (DFG). He extended his stay as a Scientific Fellow in Irvine's laboratory until 1970, with repeated visits to Gideon Goldstein's laboratory at the NIH in Bethesda, MD, USA. From 1970 to 1977, he joined Helmuth Deicher and Fritz Hartmann at the Department of Internal Medicine, Medical University of Hannover. He worked as, what nowadays would be called, a “clinician scientist,” doing research in the lab and practicing in the clinic. In 1977, he became Director of the Department of Internal Medicine III and the Institute of Clinical Immunology at the University of Erlangen, a position that he held until his retirement in 2006. After which he became Director Emeritus, and a Member of the Division of Molecular Immunology of the Nicholas Fiebiger-Zentrum, Erlangen. Throughout his scientific life, Jochen Kalden was fascinated by autoimmunity and diseases driven by this disorientation of the immune system, a system of cells designed to protect the integrity of “self.” Starting from a small laboratory in Hannover, he established an impressive and productive research center in Erlangen, concentrating on the immunology of chronic inflammatory rheumatic diseases, in particular rheumatoid arthritis (RA) and lupus erythematosus (LE). A long list of achievements, described in more than 600 publications, was the result. Many young and ambitious scientists have been imprinted by Jochen Kalden and continue to pursue his scientific attitude today, both in Erlangen and beyond. To illustrate this scientific approach, a merger of basic and clinical science, immunology and rheumatology, we give just three examples. First, together with Martin Herrmann, Jochen Kalden developed the concept of impaired clearance of apoptotic cells leading to autoantibodies to chromatin and nucleic acids, a hallmark of Lupus pathogenesis [1]. Second, when it turned out that in many patients the plasma cells producing these (auto)antibodies were refractory to conventional therapies, as indeed many autoantibody-secreting plasma cells are in chronic inflammatory diseases, Jochen and Reinhard Voll suggested the use of drugs approved for the treatment of myeloma cells, that is, transformed plasma cells, to treat patients with antibody-mediated chronic autoimmune diseases, showing the efficacy of this approach in a mouse model of LE [2]. This approach was then directly translated to human disease and shown to be effective in LE patients, highlighting the relevance of (long-lived) plasma cells secreting pathogenic antibodies as a therapeutic target to treat antibody-mediated, refractory immunopathology [3]. Third, while there is still debate on the contribution of antibodies to the pathogenesis of RA, the crucial role of cytokines produced by T lymphocytes, myeloid cells, and other cells in the environment of immune responses has become evident from the treatment of RA patients with antibodies against such cytokines, in particular TNF-α. The first clinical test demonstrating the efficacy of an antibody against TNF-α in RA, a landmark paper of rheumatology, included Erlangen, under the leadership of Jochen Kalden, as one of the four centers involved [4]. The establishment of biologicals has added a new dimension to the therapeutic options in rheumatology, and this development was driven decisively and enthusiastically by Jochen Kalden. Jochen Kalden loved to organize scientific meetings, where basic immunology met applied, clinical immunology. “Targeted Therapies,” organized since 1999, together with Ferdinand Breedveld, Leiden, and Josef Smolen, Wien, put emphasis on basic science as a source of targets for new immunological drugs. Together with Klaus Eichmann and Fritz Melchers, he organized the 7th International Congress of immunology 1989 in Berlin. His immense engagement, his diligence, his diplomatic skills, his humor, his fighting nature, and his fun for good parties helped to make this Congress one of the best that the International Union of Immunological Societies has hosted. Jochen Kalden created opportunities for science in national and international scientific advisory and supervisory boards, boards of trustees, committees, evaluation groups, delegations, memberships, and Foundations. He was President of the German Society for Immunology (1983–1990), the German Society for Rheumatology (1993–1994), and the European League against Rheumatism (EULAR) (1999–2005). His achievements have been honored with numerous awards, among them the Georg Zimmermann Award for Cancer Research (1976), the International Prize of the Japan College of Rheumatology (2005), the Master of the American College of Rheumatology, the Carol Nachman Award (2013), numerous honorary memberships in scientific societies, honorary doctorates from the Medical Faculty of the University of Lund (2005), the Medical Faculty of the Charite Berlin (2008), and the Medical School Hannover (2014). He was a member of Leopoldina and of the Bavarian Academy of Sciences, and received the Cross of Merit on Ribbon of the Federal Republic of Germany and the Bavarian Order of Merit. In the late 1980s, Jochen Kalden became one of the founding fathers of the Deutsches Rheumaforschungszentrum (DRFZ) in Berlin, a research center devoted to the investigation of the cellular and molecular basis of rheumatic diseases, in liaison with the Charité university medicine. A model to merge basic and clinical science, immunology and rheumatology, interdisciplinary and independent, with the option to pursue long-term projects and to ask fundamental questions, the DRFZ has now been driving developments for 30 years, providing new concepts regarding the immunological basis of rheumatic diseases, and identifying new targets and therapeutic strategies. His vision of modern rheumatology materialized, and Jochen Kalden remained attached to the DRFZ, as a great visionary of modern rheumatology and immunology.