CXCR4 and gastric cancer: Several previous studies have shown that SERPINB3 up-regulation caused by SDF-1/CXCR4/NF-kappaB pathway and HIF-2α-generated under hypoxic conditions separately facilitates the migration and invasion of gastric cancer (24) and hepatocellular carcinoma cells (25), exhibits superior spherogenic ability and invasion capacity of cholangiocarcinoma (26).