For example, high levels of CYP1B1 expression in breast tumor tissues was reported to be associated with significantly increased breast cancer risk39, based on the observation that high CYP1B1 expression in breast cancer cells can evoke changes in their response to drugs that are substrates of CYP1B1, thus influencing the metabolism or activation of environmental carcinogens40. Here, CYP1B1 is linked to breast carcinoma.