We used the search terms (“osteogenic sarcoma” OR “bone sarcoma” OR “primary osteosarcoma” OR “BONE”) AND (“Osteopontin” OR “Sialoprotein 1” OR “secretory phosphoprotein 1”) OR (“Uropontin” OR “SPP 1” OR “OPN”). The gene discussed is SPP1; the disease is bone sarcoma.