HOXB13 and ductal breast carcinoma in situ: To assess the extent of CpG methylation within the HOXB13, HNF1B, HLXB9 and CGI 7:48 target sequences, primary breast tumors were also subjected to bisulfite DNA sequencing together with their matching normal tissues (DCIS case number 57 and stage I case numbers 4b and 233).