While neither GnT-V nor matriptase was expressed in normal thyroid tissue, positive staining for matriptase and GnT-V was observed in 52/68 and 66/68 cases of papillary carcinomas, 3/23 and 10/23 cases of follicular carcinomas, 5/13 and 9/13 cases of follicular adenomas, and 11/28 and 6/28 cases of anaplastic carcinomas, respectively. This evidence concerns the gene MGAT5 and undifferentiated carcinoma.