AUTHOR=Yim Wai Yen , Li Chenghao , Tong Fuqiang , Hou Jincheng , Chen Yuqi , Liu Zongtao , Wang Zihao , Geng Bingchuan , Wang Yixuan , Dong Nianguo TITLE=Circadian immune system in solid organ transplantation: a review article JOURNAL=Frontiers in Immunology VOLUME=Volume 16 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2025.1556057 DOI=10.3389/fimmu.2025.1556057 ISSN=1664-3224 ABSTRACT=The innate and adaptive immune systems are intricately regulated by the circadian clock machinery. Recent clinical investigations have shed light on the influence of timing in organ procurement and transplantation on graft survival. In this review, we explore various mechanisms of immunological functions associated with the steps involved in organ transplantation, spanning from surgical harvesting to reperfusion and linking to the circadian rhythm. A deeper understanding of these processes has the potential to extend the principles of chrono-immunotherapy to the realm of organ transplantation, with the aim of enhancing graft durability and improving patient outcomes. This review concludes with some perspectives on future directions in this exciting and still evolving field of research.