In these co-culture systems, elimination of p110δ activity additionally led to decreased secretion of the chemokines CCL2, CCL3 from CLL cells, CXCL13 from stromal cells, various survival factors from NLC and inhibited the chemotaxis of B-CLL to CXCL12, CXCL13 and stromal cell lines (Hoellenriegel et al., 2011). Here, CXCL12 is linked to B-cell chronic lymphocytic leukemia.