As expected, a significant positive correlation was found between the secretion of u-PA and MMP-2/MMP-9 and a significant negative correlation between u-PA and TIMP-2 and between MMP-2/MMP-9 and TIMP-2 secretion by NM treatment of osteosarcoma and rhabdomyosarcoma cells. This evidence concerns the gene TIMP2 and rhabdomyosarcoma.