Abstract: To investigate the role of B7H4 in the development of colon and rectal cancer(CRC). Method: The expression of B7H4 in 40 excised colon and rectal tumors was evaluated immunohistochemiscally. Results: B7H4 was high expressed (80.0%)in colon and rectal cancer. No relationship was found between the expression of B7H4 and sex, age, histology type, pathology stage, cell differentiation, or lympha metastasis. However, significantly fewer TILs was identified in B7H4positive tumor specimens than in B7H4negative tumor specimens. Conclusion: ①B7H4 may be a new marker of diagnosis for colon and rectal cancer;② These results suggest that the expression of B7H4 on tumor tissue may contribute to negative regulatory immunue responses against TILs in colon and rectal cancer. The blockade of B7H4 in colon and rectal cancer might be one strategy to pursue for future immunotherapy in colon and rectal cancer.

Key words: B7-H4, TILs, Colorectal neoplasms, Immunohistochemistry