PI3Kδ inhibition with idelalisib significantlyreduces CLL cell migration in response to CXCL12 and CXCL13, as well as high CXCL13plasma levels in patients treated with idelalisib (Hoellenriegel et al. 2011). This evidence concerns the gene CXCL13 and B-cell chronic lymphocytic leukemia.