PBX2 and neoplasm: For understanding the synergistic effect of HOXA6 and PBX2 on promoting tumor metastasis in vivo, we injected cells transfected with AGS/Lenti-vector, AGS/Lenti-HOXA6 or AGS/Lenti-HOXA6-PBX2 shRNA that expressed green fluorescent protein (GFP) into nude mice via tail vein injection to examine lung metastasis.