The T-47D and HCC1954 cell lines were homogeneously methylated at 100%, the MFM-223 cell line was moderately methylated, and the ZR-75-1 and HCC1569 cell lines were methylated at low levels for CDKN2A. All the breast cancer cell lines tested were unmethylated for BRCA1. The gene discussed is BRCA1; the disease is breast cancer.