SPP1 and lung cancer: 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.