The immune system is a host defense system that organisms have acquired in order to survive while being exposed to numerous foreign substances. However, the immune system is not always perfectly regulated. In autoimmune diseases, excessive immune activation leads to chronic inflammation.On the other hand, the immune cells have difficulty eradicating tumor tissue. The immune system plays a central role in the inter-organ communications through its interaction with multiple organs such as the skeletal, nervous, cardiovascular, and digestive systems. In each tissue, immune cells interact in complex ways with epithelial cells, fibroblasts, parenchymal cells and vessels. In particular, bone marrow is the site of maintenance and differentiation of hematopoietic stem cells, and we have revealed the immune-bone crosstalk involving in the pathogenesis of various skeletal diseases. By deciphering the immune-centric multicellular networks, this research unit aims to elucidate the mechanisms how the immune dysregulation causes the onset and progression of diseases, including inflammatory diseases, locomotive diseases, cancer and lifestyle diseases, through interdisciplinary collaborative research, leading to development of medical and healthcare innovations.