Furthermore, we investigated the involvement of phosphoinositide 3‐kinase (PI3K)/Akt and mitogen‐activated protein kinase (MAPK)/Erk1/2 signaling pathways and PI3K subunits in EMT induced by OPN, the potential roles of OPN‐PI3K‐EMT on lung cancer cell movement and proliferation, and potential values as therapeutic approach to lung cancer. The gene discussed is MAPK3; the disease is lung cancer.