Two of the CDX2-negative primary CRCs (28.5%) were poorly differentiated adenocarcinomas, compared with three poorly differentiated primary CRCs (2.2%) in the CDX2-positive group (P = 0.02), confirming the previous studies reporting that CDX2-negative CRCs were more likely to be poorly differentiated [18, 23]. This evidence concerns the gene CDX2 and adenocarcinoma.