CXCL12 and acute lymphoblastic leukemia: We ruled out a role for LTβR signaling in MSCs in promoting ALL homing to the BM by transplanting 3×106 ALL cells into control or LTβR∆ mice (Figure 4A), in agreement with prior studies showing that LTβR signaling in MSCs does not control CXCL12 expression under homeostatic conditions (Zehentmeier et al., 2022).