Additionally, as highlighted by studies of lymphocyte trafficking into tumor infiltrated BM compartments, a potential problem with tumor-bearing animal models is the fact that immense tumor growth in the BM compartment can destroy stromal cells and suppress their ability to produce SDF-1α, dampening the potential for CXCR4-mediated migration and infiltration into the BM (46, 47). This evidence concerns the gene CXCL12 and neoplasm.