As depicted in Table 1, there were no significant differences observed in terms of age, gender, tumor size (longest diameter), pN stage, expression of Carbohydrate antigen 199 (CA199), or expression of carcinoembryonic antigen (CEA) between low-grade and high-grade rectal cancers (p values ranging from 0.085 to 0.703). This evidence concerns the gene CEACAM5 and rectal cancer.