Analysis of cell cycle (Fig. S3B) or apoptosis (Fig. S3C) of B-ALL cells from an MMP-9-deficient versus a wild type BMM did not reveal significant differences, suggesting that the observed differences in survival of wild type versus MMP-9 KO mice were not due to alterations in homing, cell cycle, or apoptosis of leukemia cells [1]. The gene discussed is MMP9; the disease is leukemia.