CXCR5 also known as BLR1, CD185, MDR15 is a multi-pass membrane protein that belongs to the CXC chemokine receptor family. CXCR5 plays a crucial role in the immune response by mediating the migration of B cells to specific sites within secondary lymphoid tissues, such as the spleen and Peyer′s patches. Upon binding of its ligand, the chemokine CXCL13, CXCR5 initiates multiple intracellular signaling pathways that regulate cell proliferation, survival, and migration. CXCR5 is expressed in both mature B cells and follicular helper T cells, and responds to CXCL13 gradient to control lymphocyte migration toward secondary lymphoid tissues.