Although the signaling pathways activated downstream of the GPCR CXCR5 have not been fully analyzed, it is known that this receptor couples to the PI3K/Akt, MEK/ERK, and Rac pathways to induce multiple cellular responses, not only in immune cells but also in cancer cells, as it will be discussed in other sections of this review. Here, CXCR5 is linked to cancer.