Interestingly, BRCA1 promoter hypermethylation was associated with the aggressive characteristics of breast cancer, including Scarff–Bloom–Richardson (SBR) grade III, elevated levels of ki67 expression, the overexpression of the oncogene human epidermal growth factor receptor (Her2), and the loss of estrogen and progesterone receptor expression. This evidence concerns the gene BRCA1 and breast cancer.