CXCL13 and cancer: The complex CXCL13–CXCR5 intratumoral interaction network contains both autonomous and nonautonomous responses to cancer cells, which may further vary depending on the specific cancer types, especially CXCR5 expression status on the tumor cell surface.44 When the tumor cell expresses CXCR5 itself, CXCL13 can directly act on cancer cells to promote proliferation, migration, and invasion.