CD185, also known as CXCR5 （C-X-C motif chemokine receptor 5）, is a seven-transmembrane G protein-coupled receptor primarily expressed on mature B cells, follicular helper T cells （Tfh）, and certain memory T cell subsets. It is essential for lymphocyte trafficking, particularly in directing T cells to B cell follicles within germinal centers in response to its ligand, CXCL13. CD185 plays a critical role in B cell maturation and the formation of high-affinity antibodies by facilitating interactions between Tfh cells and B cells. Additionally, it is involved in the regulation of neural stem cells and neuronal regeneration.