CD200R1 (Cluster of Differentiation 200 Receptor 1): CD200R1 is a member of the immunoglobulin superfamily that serves as a key regulator of immune responses and cellular interactions. This receptor is predominantly expressed on various immune cells, including macrophages, dendritic cells, and B cells. Its primary ligand, CD200, is present on a wide range of cell types and functions as a suppressive signal to modulate immune activity. The interaction between CD200R1 and CD200 initiates inhibitory signaling pathways that suppress inflammatory responses and promote immune tolerance. Furthermore, CD200R1 signaling plays a crucial role in maintaining immune homeostasis and preventing overactivation of the immune system.