In vivo, HOXA6 synergizes with PBX2 to accelerate tumour metastasis. (A, B) All mice were sacrificed 4 weeks after tail vein injection of vector, HOXA6 + Src shRNA or HOXA6 + PBX2 shRNA 2. (A) and whole-body white light images. (B) orthotopic tumours from mice lung metastases. (C) Haematoxylin and eosin (H&E) staining of lungs was performed in samples from mice. (D) Metastatic lesions in the lung were counted. (E) The expression of HOXA6, PBX2 and E-cadherin in the lung metastasis of GC was detected through immunohistochemistry method. (F) E-cadherin expression in tumours derived from AGS cells was detected by qPCR. ***, P < 0.01, vector versus HOXA6; HOXA6 versus HOXA6-PBX2 shRNA; *, P > 0.05, vector versus HOXA6-PBX2 shRNA. Scale bars in C and E represent 100 μm.