CXCL12 and B-cell chronic lymphocytic leukemia: Interestingly, HIF-1α inhibition also affects the SC component, resulting in a transcriptional downregulation of several target genes, including CXCL12. Therefore, the targeting of HIF-1α acts both at the leukemic cell- and SC-level, abrogating the pro-survival effect exerted by stroma interactions on CLL cells and also counteracting the protection toward fludarabine-induced cell death.