HIF-1α stimulates the miR-146a expression, which lowers the level of CXCR4, while low expression of miR-146a in AML was correlated with high expression of CXCR4, which through his ligand CXCL-12, stimulates the cell harboring in the microenvironment of the BM and was found to be overexpressed in 25%–30% of AML cases (46, 113). The gene discussed is CXCR4; the disease is acute myeloid leukemia.