In addition, Cyr61-promoted EMT is mediated by αvβ5 integrin, Raf-1, mitogen-activated protein kinase kinase (MEK), extracellular signal-regulated kinase (ERK), and Elk-1 signaling pathways, and may be involved in the regulation of EMT in osteosarcoma. Here, CCN1 is linked to osteosarcoma.