MTOR and osteosarcoma: Accordingly, the association of the Akt/mTOR pathway with metastatic progression has been reported in other cancer types, including colorectal cancer [29–31], hepatocellular carcinoma [32–34], endometrial cancer [35, 36], ovarian cancer [37], gastric cancer [38–40], melanoma [41], glioma [42, 43], pancreatic ductal adenocarcinoma [44], nasopharyngeal carcinoma [45, 46], osteosarcoma [47–50], renal cell carcinoma [51–53] and prostate cancer [54–56].