The event was opened by Prof. Gerd Geisslinger, head of Fraunhofer ITMP and spokesperson of Fraunhofer CIMD, with an overview of the current status and the further goals, tasks and work of the cluster. Prof. Frank Behrens, deputy director of Fraunhofer ITMP and science coordinator of Fraunhofer CIMD, took over the function of moderator and guided the audience through the event. The first part of the event was dedicated to the topics of clinical research and data sovereignty. Dr. Thorsten Ruppert, Senior Manager Research, Development, Innovation at the German Association of Research-based Pharmaceutical Companies (vfa) told in his presentation about the strengths and weaknesses of clinical research in Germany and which steps are necessary to strengthen clinical research in Germany. Prof. Frank Ückert, director of the Institute for Applied Medical Informatics at the University Medical Center Hamburg-Eppendorf, gave an insight into how medical data can be used and shared and which hurdles have to be overcome.

Before and after the lunch break, some of Fraunhofer CIMD's work was presented. Here, the main focus was on the established drug platforms "RNA therapeutics" (presented by platform leader Prof. Thomas Thum), "Cell and gene therapeutics" (presented by platform leader Prof. Ulrike Köhl), "Aptamers and tolerogenic protein complexes" (presented by platform leader Prof. Harald Burkhardt) and "Proximity-inducing drugs" (presented by Dr. Schara Safarian). In addition, the platform "Alternative Methods for Animal Testing" was presented by PD Dr. Katherina Sewald. Furthermore, Dr. Eduard Resch presented the results of a Fraunhofer CIMD project dealing with the characterization of COVID patients using multi-omics analyses.

During the lunch break, participants were able to enjoy an extensive buffet and had time to look at and be introduced to the 40 posters on display. During the coffee break in the afternoon there was also plenty of time to talk about the posters.

Before and after the afternoon coffee break, the lectures were dedicated to the topic of "Digital Medicine". Dr. Barbara Höfgen, Head of Digital Health Applications (DiGA)-Fast Track at the Federal Institute for Drugs and Medical Devices (BfArM), went into detail on the topic of digital health applications. She reported on how these are developed, which regulations have to be observed, to what extent artificial intelligence is used and what effects this has, and how the data protection regulation is complied with. Dr. Tine Lewi, Senior Director, Global Data, Platforms & Partnerships at Janssen Pharmaceuticals, LLC, presented opportunities for scientific collaborations via data networks. In turn, Prof. Horst Hahn, Institute Director of Fraunhofer MEVIS, presented German initiatives for digital medicine. Prof. Hahn presented initiatives such as the Medical Informatics Initiative, nfdi4health, Research Data Center Health (FDZ Gesundheit), NAKO Health care study, RACOON and other networks and projects.

The last part of the event was dedicated to perspectives in immunology. Dr. Thomas Hanke, Head of Academic Partnerships at Evotec International GmbH, gave an insight into new drug classes and general perspectives in the field of immune-mediated diseases. Prof. Axel Dignaß, Chief Physician, Medical Clinic I at the University Hospital Frankfurt, presented the current status and future prospects from a medical perspective, especially in the field of inflammatory bowel diseases. Prof. Kay Tetzlaff, Head of Medicine in the field of inflammation at Boehringer Ingelheim, closed the session with a presentation on challenges in drug development in the field of immune-mediated diseases.

The fourth day of Immune Research was a successful continuation of networking, collaboration and cooperation opportunities along the 4D within the entire Fraunhofer-Society and beyond. After the many virtual events of the last years, it was very gratifying for everyone to see each other again in person and to exchange ideas in person. We are looking forward to the next Day o Immune Research and hope to welcome many of the participants again.