Silibinin inhibits the expression of urokinase-type plasminogen activator (u-PA) and MMP-2 in human osteosarcoma MG-63 cells by down-regulating the induction of adhesion spot kinase and ERK-dependent c-jun/activator protein-1 (AP-1) (Hsieh et al., 2007). This evidence concerns the gene PLAU and osteosarcoma.