Comparatively, we found no difference in the overall level of CDX2 expression between matched primary and metastatic tumours (Fig. 2C), as well as a significant positive correlation in CDX2 expression levels between individual matched primary and metastatic cases (Fig. 2D), collectively indicating concordant CDX2 expression between matched primary and metastatic lesions. This evidence concerns the gene CDX2 and metastatic neoplasm.