CXCL12 and acute myeloid leukemia: Functionally, single-cell transcriptome demonstrated that LEPR + mesenchymal stem cells are the most important leukemic support cell that is dysfunction in AML, and a series of niche factors that induce down-regulation by AML were identified, such as CXCL12, KITL, ANGPT1, and VCAM1 (Baryawno et al., 2019).