CXCL13 and B-cell chronic lymphocytic leukemia: Ibrutinib induces apoptosis in CLL cells in the presence of pro-survival CLL elements, as well as suppression of CLL cells viability and growth, leukemic cells migration toward tissue-homing chemokines (CXCL13, CXCL12), and downregulation of BCR-dependent chemokines (CCL3, CCL4) production by CLL cells [157].