High levels of XPO1 protein are observed in ovarian carcinoma, glioma, osteosarcoma, pancreatic, cervical, and gastric cancers, are associated with high serum levels of ALP (alkaline phosphatase), and are correlated with increased tumor size, negative histological grade, and poor progression-free (PFS) and overall survival (OS) in human osteosarcoma. This evidence concerns the gene XPO1 and gastric cancer.