CXCR4 and B-cell chronic lymphocytic leukemia: Compared to 2D culture, we anticipated modulated expression of both CXCR4 and CCL4 in primary CLL cells co-cultured with M2-10B4 in a 3D environment, as these molecules are associated with the interaction between BMSCs and CLL cells (Burger, Burger & Kipps, 1999; Trimarco et al., 2015).