PXR contributes to the chemotherapy outcome by interfering with the metabolism, drug resistance, tumor sensitivity, apoptosis and pharmacokinetics parameters of many chemotherapeutic agents, such as tamoxifen, irinotecan, vinblastine, doxorubicin, paclitaxel, cisplatin and ixabepilone in cancer cell lines and patients [11,14]. This evidence concerns the gene NR1I2 and neoplasm.