Together, this study demonstrated that kaempferol attenuated the Mitogen-activated protein kinases (MAPK) signaling pathways including ERK, JNK and p38 and resulted in the decreased DNA binding ability of AP-1, and henceforth, the reduction in the expression and enzymatic actions of MMPs (2, 9) as well as uPA, contributing to the inhibition of metastasis of osteosarcoma [35]. This evidence concerns the gene PLAU and osteosarcoma.