FOXD3 and osteosarcoma: Increasing evidence has shown that lncRNA FOXD3-AS1 is abnormally expressed in various human diseases, including lung cancer (24–28), breast cancer (29, 30), cervical cancer (31, 32), nasopharyngeal carcinoma (33, 34), osteosarcoma (35), colorectal cancer (36), melanoma (37, 38), liver cancer (39), thyroid cancer (40), neuroblastoma (41), glioma (42), allergic rhinitis (43), retinal infection with Toxoplasma gondii-ocular toxoplasmosis (44), ischemic stroke (45), myocardial ischemia (46, 47) and acute respiratory distress syndrome (48).