MT1-MMP is also upregulated in HSPC following treatment with G-CSF, and we and others postulated that MT1-MMP facilitates the egress of HSPC from the bone marrow (BM) to peripheral blood (PB) [18,19,20].We and others also reported that leukemic blasts from BM or PB of acute myeloid leukemia (AML) patients secrete soluble MMP-2 and MMP-9 and proposed that these MMPs play a role in leukemic dissemination [21,22,23,24,25]. The gene discussed is MMP2; the disease is acute myeloid leukemia.