HS3ST2 and ductal breast carcinoma in situ: HS3ST2 hypermethylation was found at a high frequency in ductal carcinoma in situ of breast [9] and in cytology specimens of cervical intraepithelial neoplasia 3 (CIN3) [15], suggesting HS3ST2 hypermethylation probably occurs early during malignant transformation of the breast and cervix.