Thus, we evaluated the impact of the combined liposomal therapy with SIM and DMXAA on intratumor production of metastatic promoters such as HIF-1α and pAP-1 c-Jun, and on the activity of MMP-2 and MMP-9, both of which are activated under hypoxia and degrade the extracellular matrix, facilitating cancer cell dissemination. This evidence concerns the gene MMP9 and cancer.