[The blood ecosystem: from concept to practice]

The introduction of the blood ecosystem concept marks a paradigm shift in hematology from traditional cell- or organ-centered analyses toward a framework focused on cross-organ interactions characterized by systemic integration, connectivity, openness, and dynamic regulation. This framework emphasizes blood as a dynamically coupled network that integrates whole-body homeostasis, rather than a collection of isolated components. Enabled by advances in single-cell multi-omics, spatial profiling, and artificial intelligence-based analytical approaches, the blood ecosystem can now be interrogated with unprecedented resolution and quantified at the system level. Blood ecosystem research has not only advanced precision diagnosis and treatment of hematologic diseases, but has also expanded into non-hematological disorders by elucidating mechanisms such as circulating molecular signaling and clonal hematopoiesis, thereby uncovering principles of cross-organ pathological evolution. Together, this framework provides a foundation for the development of a precision medicine paradigm centered on system-level prediction, intelligent intervention, and ecological reconstruction.