MMP9 and chronic myelogenous leukemia, BCR-ABL1 positive: As revealed by the punctate staining pattern for MMP-9 by immunohistochemistry, however, these high levels of MMP-9 in healthy controls and CML patients were likely due to MMP-9 production by myeloid cells compared with a more diffuse staining pattern in B-ALL patients (Fig. S11C).