ZEB1 and cancer: First, while the overall homing/migratory capacity of Zeb1−/− LMPPs after transplantation appears to be unimpaired, as evidenced by equivalent engraftment during the first week (Figure 1D), it is possible that B-cell and macrophage lineages derived from Zeb1−/− LMPPs at later time points in transplantation develop Zeb1 dependency for migration from the bone marrow to the spleen, congruent with the well-established role for Zeb1 in cellular trafficking in other tissues and in the setting of cancer metastasis [8,30].