CXCR4 and leukemia: Results revealed that the expression of CXCR4 in leukemia cells in the TGF-β conditioned MSCs co-culture system had a tendency to increase compared with the ALL cells cultured alone, but had no statistical difference between the group in Nalm-6 cells, adding a certain dose of AMD3100 to the co-culture system could effectively inhibit the expression of CXCR4 in TGF-β conditioned MSCs and ALL cells (P < 0.05; Figures 3B,C).