Moreover, in osteosarcoma cells, miR-199a-3p targeted mTOR, mesenchymal to epithelial transition factor(Met), signal transducer and activator of transcription 3(Stat3), adenylate kinase 4(AK4), and AXL receptor tyrosine kinase (AXL) respectively, blocking the proliferation, invasion, and metastasis of tumor cells through a complex signaling network pathway [54,55,56]. The gene discussed is AK4; the disease is neoplasm.