JUN and central nervous system cancer: Emodin can also effectively inhibit HA-induced matrix metalloproteinase (MMP) secretion and the invasion of glioma through inhibition of the focal adhesion kinase (FAK), the extracellular signal-regulated kinases 1/2 (ERK1/2), protein kinase B (Akt/PKB) activation and partial inhibition of the activator protein-1 (AP-1), and the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-kappaB) transcriptional activities.