IL7 and acute lymphoblastic leukemia: To test if CXCR4 antagonism also prevents ALL-induced IL7 downregulation in BM MSCs, we transferred 3×106 ALL cells into Il7GFP/+ mice and treated them with an orally bioavailable CXCR4 antagonist (Dale et al., 2020) or with vehicle by daily gavage (Figure 5E).