MMP9 and osteosarcoma: Our current results also presented that both PD98059 (MEK/ERK pathway inhibitor) and miltefosine (AKT inhibitor) both inhibit the expression of tumor progression-associated proteins (VEGF, MMP-9, Cyclin-D1, C-FLIP, MCL-1, and XIAP) in osteosarcoma U-2 OS cells in vitro (Figure 4F,G).