CXCL13 and breast cancer: CXCL13 has been shown to increase the expression and secretion of RANK ligand (RANKL) from the tumor cells themselves [105,106,107], and RANKL has been shown to contribute to secondary lymphoid organ formation [109,110]; yet current data on RANKL expression in OSCC and breast cancer correlate with a more invasive phenotype [108,111,112].