CXCR4 and acute lymphoblastic leukemia: The initial clinical trials with plerixafor, BL-8040, Ly2510924, and ulocuplumab discussed above have demonstrated the feasibility and safety of combining CXCR4 inhibitors with chemotherapy in patients with AML or ALL and provided in vivo evidence for disruption of the CXCR4/CXCL12 signaling axis.