CYP3A4 and breast cancer: This HCB modulation is similar to that observed by Hsieh et al. [33], who determined that the treatment of human breast cancer cells with di(2-ethylhexyl)phthalate, an environmental pollutant that is a weak agonist of AhR, reduces the antitumor response to doxorubicin due to the increase in CYP3A4 and CYP2C8 expression, which in turn increases the metabolization rate of the drug.