The Cluster of Excellence “Precision Medicine in Chronic Inflammation” (PMI) mourns the loss of Prof. Dr. med. Steffen Gay, who passed away on July 16, 2025, at the age of 77. In him, the field of inflammation medicine loses a pioneering thinker in interdisciplinary clinical immunology, an internationally respected researcher, and a passionate teacher and mentor. The entire PMI Cluster, including its Executive Group and Steering Committee, extends its heartfelt condolences to his wife, Prof. Dr. med. Renate Gay, and to his family.

Prof. Dr. med. Steffen Gay was born in 1948 in Geyersdorf in the Erzgebirge region (today Annaberg-Buchholz, Saxony). From 1966 to 1973, he studied medicine at the University of Leipzig, where he also earned his doctorate (Dr. med.) In 1973. Early in his career, he focused on cell and tissue-based research. He then worked at the Max Planck Institute for Biochemistry in Munich. Beginning in 1976, Gay continued his scientific career in the United States, with positions in biomedical research (including in New Jersey) and at the University of Birmingham in Alabama. There, he worked in the Department of Clinical Immunology and Rheumatology and was appointed Professor of Medicine in 1984. In parallel, he was involved in various interdisciplinary programs, including collaborations with pathology, dermatology, and the cancer center. He also led a WHO center for the classification and diagnosis of rheumatic diseases.

In 1996, he accepted an appointment at the University Hospital Zurich, where he became Professor of Experimental Rheumatology and Senior Physician. He established and internationally connected the Center for Experimental Rheumatology there. He later also served as an advisor to the department. Under his leadership, Zurich developed into a major European hub for translational rheumatology research and became part of further WHO collaborative networks for molecular strategies in rheumatic diseases.

Scientifically, Gay was particularly influential in advancing the understanding of the molecular and cellular foundations of inflammatory-rheumatic diseases. He was among the early advocates for the systematic investigation of epigenetics as a regulatory factor in rheumatoid arthritis and other inflammatory processes. It was important to him to link basic research with potential therapeutic approaches.

For decades, Prof. Gay actively promoted international scientific exchange and supported the next generation of rheumatologists. Many of today’s leading rheumatologists owe him critical inspiration and opportunities for collaboration between Europe and the USA. Prof. Gay served for many years on the Scientific Advisory Board of the PMI Cluster. It is thanks in part to his efforts that the cluster has now secured new funding. In recognition of his contributions, Gay received numerous honors, including the prestigious Carol Nachman Prize in 1978 – the highest award for rheumatology in Germany. The German Society for Rheumatology also honored his outstanding contributions in 2008 with the Kussmaul Medal, which he received together with his wife Renate. Steffen Gay was an honorary member and active member of various national and international organizations, including the Leopoldina, EULAR, and DGRh.

The Cluster of Excellence PMI bids farewell to an extraordinary scientist, a highly esteemed teacher, rheumatologist, mentor, and friend, who left a lasting mark on the field of inflammation medicine. Our deepest sympathies go out to his wife, his family, and all those who had the privilege of working with him.