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 mainly expressed on various immune cells, including macrophages, dendritic cells, and B cells. Its primary ligand, CD200, is present on a wide variety of cell types and functions as a suppressive signal to regulate immune activity. The interaction between CD200R1 and CD200 activates inhibitory signaling pathways that reduce inflammatory responses and promote immune tolerance. Furthermore, CD200R1 signaling plays a crucial role in maintaining immune homeostasis and preventing excessive immune activation.