CXCR5 is a G protein-coupled receptor belonging to the chemokine receptor subfamily. Once it binds to its ligand (chemokine CXCL13), CXCR5 will activate multiple intracellular signal transduction pathways, thereby regulating cell proliferation, survival and migration. CXCR5 is expressed in mature B cells and follicular helper T cells, and it responds to the CXCL13 gradient, thereby regulating the migration of lymphocytes to secondary lymphoid tissues. CXCR5 is also highly expressed in primary breast cancer cells, which is related to their growth and metastasis tendencies.
