CXCL12 and B-cell chronic lymphocytic leukemia: We tested whether the inhibitors of RAS (i.e., simvastatin), ERK1-2 (i.e., PD98059) and PI3K/AKT (i.e., idelalisib), acting at different levels of the signalling pathways, affected SC- and CXCL12-induced HIF-1α upregulation in primary CLL cells (Figure 2A).