Indeed, the concept of antioestrogenic interventions has been advanced with the reduction of risk from breast cancer by using tamoxifen (Cuzick et al, 2003) or raloxifene (Cummings et al, 1999), as well as suggestions for the evaluation of a number of aromatase inhibitors as chemopreventives in high-risk postmenopausal populations. Here, CYP19A1 is linked to breast cancer.